Are Matt Damon and Mark Wahlberg Brothers?
No, Matt Damon and Mark Wahlberg are not brothers. Matt has one brother, a sculptor and artist named Kyle, and Mark has five older brothers — Arthur, Jim, Paul, Robert, and the famous Donnie (of New Kids on the Block and Blue Bloods fame). Both actors grew up in the Boston area, and they co-starred in the 2010 Martin Scorsese hit The Departed, but they are not related.
Sorry to disappoint.