Movies
* The Twilight Saga (2008-2012) - Mike Newton
* Red Riding Hood (2011) - Henry
* The Boy in the Striped Pajamas (2008) - Bruno
* A Lot Like Love (2005) - Kevin
* Unaccompanied Minors (2006) - Spencer
* The Perks of Being a Wallflower (2012) - Brad
* The Last Airbender (2010) - Prince Zuko
* Max Keeble's Big Move (2001) - Max Keeble
Television
* The Vampire Diaries (2013-2014) - Luke Parker
* Teen Wolf (2011) - Isaac Lahey
* The Nine Lives of Chloe King (2011) - Paul
* Joan of Arcadia (2003-2005) - Luke Girardi
* The Practice (2001) - Billy
* Scrubs (2004) - Young John 'J.D.' Dorian
* CSI: Crime Scene Investigation (2004) - Young Grissom
* Cold Case (2004) - Young Nick
* The O.C. (2004) - Josh
This is not an exhaustive list, but it showcases some of Michael Welch's most prominent roles. He has also appeared in a number of other films, TV shows, and theatre productions.
To find more detailed information about his filmography, you can refer to websites like IMDb or Wikipedia.