What age is Jeremiah in The Summer I Turned Pretty? Character explored, in depth

Jeremiah Fisher is not only a beach boy with a killer smile—he's one of the emotional pillars of The Summer I Turned Pretty. Team Jeremiah or just along for the drama, there's one question fans can't help but ask: What age is Jeremiah in The Summer I Turned Pretty? It’s a valid curiosity, especially when you’re trying to make sense of the love triangle, family tension, and all the coming-of-age chaos the series throws our way.

And let's be real, age is definitely something most people look at. It determines how characters make choices, deal with heartbreak, and perceive the world. Jeremiah is no different! His personality, relationships, and emotional development all rest on the fact that he's still a teenager. So, let's get to it: how old is Jeremiah actually, and why does that mean so much to his character in the show?

How old is Jeremiah in The Summer I Turned Pretty?

During the original The Summer I Turned Pretty novel by Jenny Han, the summer that it all begins is the summer Belly turns sixteen. Jeremiah is said to be the same age according to the series, which means he is still quite definitely in his mid-teens. That makes him likely to be 16 or 17 years old when the main story takes place.

Note: This is based on the original books and not necessarily the television show adaptation.

The Amazon Prime Video show remains pretty true to this timeline. While the actual age isn't driven home in each episode, the series puts both Jeremiah and Belly solidly in the 16-to-17 range for much of the narrative. So yes, referring to Jeremiah as 17 in the subsequent episodes or by Season 2 is a good and accurate judgment.

The real age gap: Gavin Casalegno vs. Jeremiah Fisher in The Summer I Turned Pretty

Here is where things become even more intriguing. The actor playing Jeremiah, Gavin Casalegno, was born in September 1999 and was 23 when he first started playing the role. That makes him around six to eight years older than his TV counterpart, depending on the season.

When shooting started on Season 1, Gavin was himself in his early 20s, playing a teenager. But due to the youthful look on his face and the emotional vulnerability he brings to the character, most people probably won't even guess the age gap. The key thing is that Gavin plays Jeremiah with just the right balance of teenage spontaneity and heart-on-the-sleeve vulnerability. And isn't that the very spirit of being 17?

Who is Jeremiah Fisher in The Summer I Turned Pretty?

Jeremiah Fisher is Susannah Fisher's younger son and the less-quiet opposite of his contemplative brother, Conrad. He's goofy, humorous, emotionally expressive, and—let's be honest—way more at ease discussing feelings than most teen boys on television. He's the type of guy who'll use humor to defuse an uncomfortable situation and then lie awake half the night agonizing over other people's emotions.

Whereas Conrad has a tendency to bottle up, Jeremiah wears his emotions on his sleeve. That does not make him immature—just different. His very openness is what makes him likable but also vulnerable. He's the kind of friend you'd want at your side during a crisis, even if he's calmly navigating through a storm of his own.

How Jeremiah's age influences his plotline in The Summer I Turned Pretty

Being a teen, Jeremiah is trying to navigate a very complicated chapter in life. He's not a kid anymore, but he's not quite an adult yet either. His age is one of the main reasons why he behaves the way he does—sometimes with complete confidence, sometimes with raw emotion and doubt.

This middle stage appears everywhere. He's coping with the pain of seeing his mom's health slipping, dealing with the complex emotions for Belly, and living under that constant shadow of being Conrad's little brother. It's a lot. And for a teenager, that stress usually manifests as explosive outbursts, jealousy, or rash decisions. But once again, it all checks out in the context of his age.

Jeremiah and Belly in The Summer I Turned Pretty: Similar in age, even more so in bondage

The dynamic between Jeremiah and Belly is one that polarizes fans—some adore the chemistry, while others are Team Conrad. Whatever can't be denied is how much their proximity in age contributes to their relationship. Both are teenagers trying to navigate life, love, and loss simultaneously. That same stage of life reunites them time and again, even when the lines get fuzzy.

Since they are about the same age, their experiences together—awkward, sweet, or painful—are always real teenage emotions. Jeremiah lacks the benefit of hindsight or emotional detachment. He's feeling everything in the moment, and that's what makes his relationship with Belly so passionate.

Emotional development or simply teen agony?

Jeremiah is the more emotionally developed Fisher brother, but don't get it twisted—there is still a 16-year-old in him. His reactions are unfiltered and sometimes irresponsible. He can be jealous, insecure, or clingy whenever he perceives he is losing somebody he loves. But again, that is not weakness. That is what 16 or 17 years old might look like in real life.

His emotional process is more about being real and less about being perfect. He messes up, discovers, and grows—and that's exactly why he's so relatable. He's not the ideal man, but he's trying his best. And isn't that kind of the point?

To answer it briefly: Jeremiah Fisher is around 16-17 years old in The Summer I Turned Pretty, both on page and on screen. The young actor playing him, Gavin Casalegno, turned 25 in 2024 but perfectly captures all the messiness, charm, and complexity of a teenager going through love, family, and self-discovery.

Jeremiah’s age in The Summer I Turned Pretty isn’t just a number—it’s the foundation of his entire character arc. He’s growing up in front of us, with all the awkwardness and intensity that comes with it. And whether you’re watching for the romance, the drama, or just the beach views, one thing’s for sure: being 17 has never looked more emotionally layered.