Thomas Ian Nicholas is an American actor, filmmaker and musician. The accolades he has received include an Independent Spirit Award, as well as a Young Artist Award nomination.

In film, Nicholas is best known for his lead roles as Kevin Meyers in the American Pie theatrical film series (1999–2012) and Henry Rowengartner in the sports comedy film Rookie of the Year (1993). He portrayed historic figures Frank Sinatra Jr. in Stealing Sinatra (2003) and Walt Disney in Walt Before Mickey (2015). Nicholas has also had lead roles in the films A Kid in King Arthur's Court (1995) and Adverse (2020), and supporting roles in Halloween: Resurrection (2002), The Rules of Attraction (2002), Please Give (2010), Bilal: A New Breed of Hero (2015), and Sheep and Wolves (2016).

In television, Nicholas had recurring roles on Fox shows as Todd Marsh on Party of Five (2000) and Nick Hutchison on Red Band Society (2014–2015). He had a main role as Joe on the Tubi mockumentary sitcom Underdeveloped (2023), and provided a lead voice dubbing role on the American version of the Cartoon Network animated series Gormiti Nature Unleashed (2013–2014).