1996–2013: Breakthrough with American Pie films
Early in his career, Scott worked at The Home Depot and the Los Angeles Zoo to support himself between acting jobs. He also appeared in the Aerosmith music video, "Hole in my Soul." In 1996, Scott made his first on-screen appearance as Moondoggie on The WB sitcom Unhappily Ever After, in the episode "Beach Party." He later landed the role of Steve Stifler in the comedy film American Pie (1999). Scott revealed that he was paid $8,000 for his supporting role in the film, which ultimately grossed over $235 million worldwide. He reprised the role in the film's three sequels: American Pie 2 (2001), American Wedding (2003), and American Reunion (2012). For his performance in American Reunion, Scott reportedly received a $5 million salary and a share of the profits.
Scott won two Teen Choice Awards for Choice Sleazebag for his portrayal of Steve Stifler in American Pie and American Pie 2, and received an MTV Movie Award for Best Dance Sequence for American Wedding. He also shared an MTV Movie Award for Best Kiss with Jason Biggs for American Pie 2.
Following the American Pie series, Scott appeared in a range of roles, including Billy Hitchcock in the horror film Final Destination (2000) and Chester Greenburg in Dude, Where's My Car? (2000), with the latter film emerging as a box office success, earning $73.2 million worldwide against a $13 million budget. He also appeared in Road Trip (2000), Jay and Silent Bob Strike Back (2001), Evolution (2001), Stark Raving Mad (2002) and Bulletproof Monk (2003). He played Peppers in Old School (2003), which emerged as a moderate commercial success. That same year, Scott co-hosted the 2003 MTV Movie Awards alongside Justin Timberlake.[12]
In 2005, Scott portrayed Bo Duke in The Dukes of Hazzard (2005), which despite negative critical reception, grossed $111 million worldwide. In 2006, he was nominated for the MTV Movie Award for Best On-Screen Team, alongside Jessica Simpson and Johnny Knoxville, for their performances in The Dukes of Hazzard.
He voiced the character Crash in Ice Age: The Meltdown (2006) and reprised the role in its sequels, Ice Age: Dawn of the Dinosaurs (2009) and Ice Age: Continental Drift (2012).In 2007, Scott played a police officer in Southland Tales, reuniting with Dwayne "The Rock" Johnson, his co-star from The Rundown (2003). The two also appeared in parody skits, including scenes from The Matrix Reloaded (2003), which were featured on The Matrix Reloaded DVD. Scott later hosted Saturday Night Live and was a guest co-host on Live with Regis and Kelly. He appeared as John Farley in Mr. Woodcock (2007) and as Jeff Nichols in Trainwreck: My Life as an Idiot (2007). His next film, Role Models (2008), received generally positive reviews and was a commercial success, earning over $92 million worldwide.
He appeared in the action-comedy Cop Out (2010) alongside Bruce Willis, Tracy Morgan, and Kevin Pollak. To prepare for the role, Scott gained weight and refrained from exercising for six months. In 2011, he starred as Doug "The Thug" Glatt in the Canadian sports comedy Goon, which emerged as a critical success and grossed $6.7 million worldwide. In 2012, he appeared in the ensemble film Movie 43, in the segment titled "Happy Birthday." That same year, Scott received an honorary medal from the Philosophical Society at Trinity College. In October 2013, he guest-starred in an episode of the FX sitcom It's Always Sunny in Philadelphia, playing Mac’s cousin, Country Mac.