Pretty Little Liars: 10 Famous Guest Stars You (Probably) Forgot About

Aria, Hanna, Emily and Spencer and Alison may have been the most popular girls at Rosewood High, but in that school's defense, the entire yearbook read like a Who's Who of teen TV royalty.

Let's look back at some of the guest stars who have become even better known since crossing paths with the Pretty Little Liars:

ADAM LAMBERT

I'm not sure which concept is harder to grasp: Grammy-nominated artist Adam Lambert (as himself) performing at a Halloween party in a small Pennsylvania town... or openly gay Adam Lambert (again, as himself) getting flirty with Aria. I guess anything can happen in Rosewood.

DIEGO BONETA

Boneta played Spencer's tennis-instructor boyfriend Alex in Season 1, before moving on to a very different group of Scream Queens.

CARLSON YOUNG

Young, who appeared in two episodes of Season 1, should probably head back to Rosewood to remind the Liars that it could always be worse. (Seriously, the stab-happy villains on MTV's Scream made "A" look like a middle-school bully.)

RYAN GUZMAN

Before starring on Fox's 9-1-1, Guzman recurred on PLL as Jake, a ridiculously handsome roadblock on Aria and Ezra's long journey to happily-ever-after.

GREGG SULKIN

Sulkin popped by Rosewood as Ezra's younger brother, before going on to star on shows like Hulu's criminally short-lived Runaways.

STEVEN KRUEGER

Much like Emily's heterosexuality, her ex-boyfriend Ben — played by Krueger, who later played Josh on The CW's The Originals — remains but a distant Season 1 memory.

CLAIRE HOLT

Speaking of Emily's sexuality and The Originals, remember when Holt recurred as Samara in the first two seasons?

PATRICK J. ADAMS

Before he was Troian Bellisario's real-life husband, the Suits star appeared in a Season 1 episode as an old college friend of Ezra's.

ROBBIE AMELL

Future Upload star Amell made only one appearance on PLL — as Noel Kahn's brother Eric — but what an appearance it was.

ARDEN CHO

You just never know who you're going to encounter in the bathroom at Rosewood High — including a future Teen Wolf star!