July 9, 2010 to October 6, 2016 [recurring]

Thorne Forrester is the youngest son of Eric and Stephanie Forrester, co-founders of fashion house Forrester Creations; Thorne was raised with his siblings, Ridge, Kristen, and Felicia Forrester. Thorne had a crush on Caroline Spencer, even though she was engaged to Ridge. When Caroline dumped Ridge for having a one-night stand before their wedding, Thorne befriended Caroline, and the friendship turned to romance. But Thorne knew Caroline still loved Ridge, so he convinced Ridge's new girlfriend, Brooke Logan, to hide a letter in which Ridge professed his devotion to Caroline. Thorne and Caroline married soon after, although Caroline was furious when she learned of Thorne's part in hiding the letter.

Thorne became frustrated by Caroline's hesitancy to be intimate; while recovering from an appendectomy, Thorne overheard Eric and Stephanie discussing a prank in which Ridge had slipped into a drunken Caroline's bed and made love to her. Hopped up on alcohol and sedatives, Thorne grabbed Stephanie's gun and shot Ridge in the head. Thorne passed out; when he woke up, he was told that Stephanie had shot Ridge, thinking he was a prowler. Thorne agreed to marriage counseling with Caroline, who wanted to reunite with Ridge; Thorne soon grudgingly granted her a divorce. Before long, Thorne turned his attentions toward Brooke's sister, Donna Logan.

Thorne later met burn victim Deveney Dickson and arranged for her to have restorative plastic surgery. But Thorne didn't know that Deveney had been burned in a car wreck after impersonating his microcephalic sister Angela, nor that "Angela" blamed Stephanie for the accident and wanted to get revenge by having Thorne re-enact his shooting of Ridge. Thorne agreed to have a drink with the lovesick Deveney after he gently let her down, not realizing Deveney had drugged it; the delirious Thorne raged as Deveney told him how Caroline had cheated on him. After Deveney handed him a gun, Thorne aimed for Ridge but threw the gun away when Ridge and Stephanie explained how Thorne had shot Ridge the first time, which Thorne had blocked from his memory.

Thorne met Macy Alexander when her mother, Sally Spectra, owner of competitor Spectra Fashions, tried to play matchmaker by locking Macy and Ridge in a stateroom on the Queen Mary during a fashion show. Thorne briefly dated Macy and Donna at the same time, but ultimately chose Macy. Neither the Forresters nor the Spectras approved of Thorne and Macy's relationship; Thorne and Macy married anyway, but separated when the strain of the families' battle became too much.

During the separation, Thorne got close to Karen Spencer, Caroline's long-lost identical twin sister. Just as Thorne asked Karen to move in with him, Macy asked for a reconciliation, and the three ended up living under the same roof. When Thorne couldn't choose between Macy and Karen, the ladies got into a food fight over him. Thorne finally decided on Macy but misinterpreted Macy hugging former suitor Jake Maclaine, prompting Thorne to settle for Karen. Thorne and Macy's attempts at communication were thwarted by Karen and her father, Bill Spencer, Sr.

Thorne lost Karen over his continuing feelings for Macy, who developed a drinking problem. Thorne found Macy passed out in an alley, after which they cleared up their misunderstandings and reconciled. But one night Thorne came home and caught Spectra designer Anthony Armando putting a drunken Macy to bed; Thorne and Macy never knew that Eric's new wife Sheila Carter, of whom Thorne disapproved, had avenged herself by spiking Macy's orange juice. Thorne left Macy again and punched Ridge to replace him on an overseas trip with Brooke, who was interfering with Ridge's marriage to Taylor Hayes.

Thorne returned for Taylor's funeral and re-established a friendship with Macy, though he briefly dated Forrester model Ivana Vanderveld. Thorne and Macy began singing together and were signed by Decadent Records, making Ivana jealous when they performed in Rotterdam, Holland. Thorne stood by Macy when she was diagnosed with throat cancer; following Macy's surgery, Thorne proposed to her. But after Thorne confronted Ivana for writing Macy a nasty fan letter, Ivana was murdered with Thorne's letter opener, and Thorne was arrested during his wedding to Macy. Learning that Anthony had stationery like Ivana's, Thorne broke out of jail and extracted a confession from Anthony, who wanted Macy for himself and killed Ivana to frame Thorne. Though Macy failed to get Anthony's admission on tape and Sally was shot in the process, Thorne was freed when Anthony was apprehended.

After Thorne finally married Macy, he performed Grease on Broadway for four months. Upon his return, Thorne befriended Claudia Cortéz, who was in the United States illegally. Thorne gave Claudia a job at Forrester, but couldn't believe it when Macy reported Claudia to immigration after catching Claudia giving Thorne a massage. Freshly divorced, Thorne began to see back-from-the-dead Taylor in a new light and saved her after she drunkenly set her nightgown on fire while pining for Ridge. Thorne stayed at Taylor's side as she healed from her burns.

When Taylor discovered she was pregnant by Ridge, who was in jail for shooting domineering designer-turned-CEO Grant Chambers, Thorne convinced Taylor to lie that the baby was his and asked Taylor to marry him. Thorne worked with Brooke to keep Ridge and Taylor apart; Thorne drugged Taylor's protein shake when she invited Ridge over to tell him the truth. Thorne relented when Taylor insisted on stopping Ridge and Brooke's wedding, but was forced to deliver Taylor's baby in his car when she went into labor en route.

Thorne was out in the cold when Taylor finally told Ridge he was a father and Macy moved on with Grant. Thorne flirted with Macy's best friend, Darla Einstein, but when Grant announced he had untreatable testicular cancer and wanted Thorne to fulfill Macy's desire for a family, Thorne kissed Macy as Grant lay dying in his hospital bed. After Grant died and Macy would only accept Thorne's friendship, Thorne, who had quit Forrester Creations over Stephanie's preferential treatment of Ridge, stepped in and saved Spectra Fashions from bankruptcy.

Thorne made a romantic connection with Brooke, which enraged Stephanie to the point she terrorized Brooke at the Forrester cabin in Big Bear. After Stephanie had a stroke and didn't remember finding Thorne and Brooke together, Thorne kept his relationship with Brooke a secret and reconciled with Macy to throw Stephanie off the scent, narrowly avoiding a surprise wedding Stephanie arranged. In Venice, Italy, Thorne caught Brooke kissing Ridge, unaware that Ridge, Taylor, and Eric had manipulated the situation to separate Thorne from Brooke. Thorne followed Macy to Amsterdam and married her, though he still thought of Brooke.

Thorne finally admitted he wanted Brooke, so Macy asked him to meet her at the Big Bear cabin for one last dance. When he got there, he found Macy and Brooke in a wrecked car trapped under a gas truck. Thorne saved Brooke, but before he could get to Macy, he was thrown back by a violent explosion that killed Macy. At Macy's funeral, Thorne scrambled to explain when Sally exposed his affair with Brooke, causing Stephanie to have a second stroke.

Thorne's relationship with Brooke hit other obstacles: Macy's half-sister, Kimberly Fairchild, kissed Thorne backstage at a fashion show while Brooke's daughter, Bridget Forrester, raised the curtain so the public would see. After Brooke left him, Thorne got drunk and was told the next morning that he and Kimberly had made love. But Thorne realized Kimberly was out of her mind with grief when he was almost hit by the photographer's light Kimberly had rigged to fall on Brooke. Thorne and Brooke reconciled and married at the Forrester mansion, even getting last-minute support from the family. Thorne's happiness was short-lived, however, when he overheard Brooke admitting that Ridge would always be her soul mate; Thorne had a vision of Macy and asked Brooke for an annulment. Later, Thorne shared a few kisses with grief counselor Tricia Quick.

In Portofino, Italy for a fashion showdown, Thorne chased Lena, a woman that reminded him of Macy, learning that "Lena" really was Macy, whose father, Adam Alexander, had saved Macy before her car exploded and took her on the run from the mob with him. Thorne was dismayed when Macy insisted on staying in Italy and marrying Lorenzo Barelli, but once Macy came home to see Sally through a heart attack, Thorne informed Macy that her marriage to Lorenzo was invalid because she had never signed Thorne's divorce papers. Thorne and Macy reconciled, but he misread Macy's goodbye to Lorenzo, got drunk, and slept with Darla, thinking she was Macy.

After Macy's returning cancer required her to have a hysterectomy, Thorne found out Darla was pregnant with his child. Thorne hoped he and Macy could raise Darla's baby, but Thorne lost Macy when she found out about his one-nighter. Thorne gratefully accepted Macy's eventual forgiveness, but watched in horror as a chandelier crashed down on her while she headlined a new club. After Sally pulled the plug on the comatose Macy off-screen, Thorne and Darla named their child Alexandria in Macy's memory, then got married.

Thorne was awarded the presidency of Forrester Creations but faced constant challenges from Ridge, who insulted Darla to the point Thorne punched Ridge. Thorne forgave Darla for accidentally handing Sally designs from Forrester's upcoming Ingenue line, but when Ridge banned Darla from the building, Thorne and Ridge demanded that Eric decide who should leave. After Eric sided with Ridge, the embittered Thorne raged that he was the only true Forrester son, as it had been revealed that Massimo Marone was Ridge's real father; Thorne threw a chair through a window and left in disgust.

Thorne became acting president of Spectra and used his Forrester client list to gain support, even stealing Forrester designs to use in a Spectra fashion show. Soon Thorne had original couture created by Spectra mainstay Clarke Garrison, former designer Amber Moore, and Thorne's sister, Felicia Forrester, challenging Forrester to a fashion showdown; Thorne lost the competition but gained Eric's respect. Thorne sold his Forrester shares and invested in Spectra, losing his money when Spectra failed to win a new fashion showdown featuring Thomas' designs. But when Stephanie discovered she was the sole owner of Forrester, Thorne got his presidency back. Later, after Spectra closed its doors, Thorne and Darla moved an ailing Sally in with them and made her a receptionist at Forrester.

Thorne was devastated when Darla fell into the path of an oncoming car and died helping Taylor's daughter, Phoebe Forrester, change a tire on a foggy night. Thorne needed Taylor's psychiatric expertise to explain things to Alexandria, and soon Thorne and Taylor resumed their romantic relationship. Thorne proposed to Taylor, but felt betrayed to learn Taylor had hit Darla while driving drunk. However, at Taylor's trial, Thorne spoke up for her, and she was released.

Thorne was forced to call off his wedding to Taylor when Alexandria blacked out Taylor's pictures with a crayon and shredded Taylor's wedding dress. Despondent, Thorne drunkenly made love to Donna, seeing Darla's face. Thorne decided to make Donna his bride until her sister, Katie Logan, took Thorne aside and revealed that Donna was only trying to make Stephanie pay for hurting Brooke. Thorne briefly bonded with Katie, though no romance developed.

Thorne helped Eric form a new company, Forrester Originals, when Ridge's half-brother, Nick Marone, took control of Forrester Creations. Thorne disapproved of Eric's relationship with Donna and helped Felicia lock Donna in the Forrester steam room to keep Donna off the runway; Thorne lost his job when Eric lapsed into a coma and Donna lowered the boom on Thorne and his siblings. Thorne knew Donna was spending time with her assistant Owen Knight, so when Eric recovered, Thorne hired Donna and Owen lookalikes to kiss for a hidden camera so Eric would divorce Donna. Thorne's scheme failed.

Thorne was suspected of giving Forrester designs to Jackie M after he made noise about Rick and Ridge getting too much attention at Forrester, but the real culprit was Rick. Thorne expected to take the president position when Rick left the company, but felt even more unappreciated when Brooke made Rick president instead. Thorne and Felicia, deeming Forrester overrun with Logans, resigned when Brooke, Donna, and Katie became models for the Royalty line. Thorne eventually returned, but soon Bill Spencer, Jr. seized Forrester and installed his new wife, Katie, as CEO. Thorne refused the vice presidency Katie offered him, instead helping to create the ugly Dare line to sabotage Bill. Thorne was upset when his niece, Steffy Forrester, got the company back from Bill and divided the stock between Ridge, Eric, Stephanie, and Taylor, while Thorne received none.

Thorne submitted to a DNA test after he realized a long-ago fling with Kelly Cooper may have sired newcomer Liam Cooper; the test revealed Bill was Liam's father. Thorne wondered if his unlucky-in-love nephew Thomas might be gay; when it turned out Stephanie had put Thomas up to lying about sleeping with Brooke to gain Stephanie's 25% share in Forrester, Thorne grumbled he was all right being "banished" to the basement with no stock because he "didn't want to have to spend that much time around you people." Thorne later tried to make a power play after Taylor came to control 55% of Forrester, but Taylor didn't want to pit her children against their father. Thorne and Taylor found romance again, which happened primarily off-screen, except for Thorne's delight at hearing Taylor say she was finally over Ridge.

Months later, Taylor returned solo and reported that she and Thorne had broken up. Thorne came home to mend fences with Stephanie when he learned she was dying from Stage IV lung cancer. After Stephanie's will made Eric permanent CEO, Thorne and Thomas unsuccessfully tried to talk Eric out of giving Rick the presidency. Some time later, a grown-up Aly returned from college, so Thorne put her to work at Forrester and sold the beach house where he'd raised her. Thorne eventually accepted a position running Forrester International in Paris, confident Aly was in good hands.

Thorne knew that Aly had issues from being bullied in school and that she'd never quite recovered from Darla's death, and began to worry when Aly claimed she was having conversations with her deceased mother. Thorne reunited with Taylor but feared Aly's reaction, which included Aly threatening Taylor with an axe. Thorne was willing to end things with Taylor until Aly's boyfriend, Oliver Jones, helped Aly accept Thorne's relationship. Then, when Ridge went missing falling out of a helicopter in Abu Dhabi, Thorne traveled there to join the search.

After Thorne and Taylor again broke-up off-screen, Thorne returned to L.A. to check on Aly due to reports she was becoming increasingly hostile. Before Thorne could take Aly back to Paris for additional therapy, Aly died in a violent confrontation with Steffy. Thorne demanded answers from Steffy following Aly's memorial; it was later said that Thorne went back to Paris and that he'd been informed the investigation into Aly's death had been closed.

The following year, Thorne came home for Eric's wedding to Quinn Fuller, a woman with a criminal past. Hearing about Quinn's misdeeds, Thorne stood with his family in boycotting Eric's wedding, but felt horrible for betraying his father when Eric collapsed from a brain hemorrhage. Thorne stayed by Eric's side until he could recuperate at home, then headed back overseas.

Feeling he'd spent enough time grieving Aly's death, Thorne moved back to Los Angeles in 2017 revealing he had learned fashion design and founded Aly Designs in tribute to his daughter. Thorne ruffled Ridge's feathers by declaring he wanted to design at Eric's side, and by making moves on Brooke that resulted in a shoving match between Thorne and Ridge. However, Thorne and Ridge patched things up when Thorne agreed to be best man at Ridge's wedding to Brooke, where Thorne reconnected with Katie, who was in a secret no-strings romance with Wyatt Spencer. Thorne kissed Katie, then, after Katie suddenly found herself single, Thorne grabbed Katie's phone by mistake but purposely deleted a reconciliation text to her from Wyatt.

After Katie and Wyatt got engaged, Thorne eagerly accepted a position designing for Forrester's youth-oriented line Hope for the Future line alongside its creator, Brooke's daughter Hope Logan. When threats against Hope were posted on the HFTF web site, Thorne and Katie hired an IT specialist and traced the cyberbullying to the computer of Sally Spectra, grand-niece of Macy's mother Sally, who had also once stolen from Forrester. Thorne fired Sally but apologized when the real culprit turned out to be Zoe Buckingham, the ex-girlfriend of Forrester intern Xander Avant. Thorne shared everyone's skepticism when Zoe snuck into Forrester and saved the HFTF showing by stepping in for an injured model; despite his original misgivings, Thorne went over Ridge's head and hired Zoe when buzz about her benefitted the company.

When Katie broke up with Wyatt, Thorne swooped in and kissed her. Before long, Thorne declared his feelings for her but didn't expect opposition from Katie's ex-husband, Bill Spencer, whom Katie felt had been neglecting their son, Will. Thorne encouraged Katie to file for sole custody of Will and married Katie just before the hearing. Thorne was happy when the judge ruled in Katie's favor, but dismayed to learn that the judge was an old friend of Ridge's whom Ridge had leaned on to determine the outcome. Thorne feared the worst when Bill found out, and was amazed when Bill let everyone involved off the hook. Agreeing with Ridge that Bill's altruism was only meant to impress Brooke, Thorne accompanied Ridge to Bill's house to tell him to stay away from Brooke, and the three men got into a fight that ended with Bill going over his second-story balcony. Thorne breathed another sigh of relief when Bill again declined to go to the cops.

Thorne became uncomfortable with Bill's increased presence in Will's life, particularly during a family dinner. Between that, still struggling with Aly and Darla's deaths, and sensing Katie still had feelings for Bill, Thorne got an annulment from Katie and moved back to Paris.

In 2022, Thorne appeared to Brooke in a dream for the show's 35th anniversary and reminisced about their relationship as a way of reminding Brooke of her value owing to problems she was having with Ridge. The following year, Thorne came home for real to attend a party thrown by Eric, only to learn that Eric was dying. When Eric collapsed and was hospitalized, Thorne butted heads with Ridge, who wanted to take Eric off of life support due to a do-not-resuscitate order; Thorne was in favor of trying an experimental treatment developed by Steffy's doctor husband, John "Finn" Finnegan. Thorne waited anxiously as Finn and Bridget performed the procedure, but Thorne did not appear on screen again after Eric woke up having survived the operation.