At the end of Guardians Of The Galaxy, the movie reveals two key bits of information about the (previously barely mentioned) father of Chris Pratt’s Peter Quill: First, that Yondu (Michael Rooker) and his gang of space outlaws were hired by Quill’s father to abduct the future Star-Lord when he was a kid, and second, that Quill’s father is a member of some unknown alien race. If those teases weren’t a clear enough setup, director James Gunn told Vulture that Guardians Of The Galaxy 2 will be “a story about fathers.” He says Guardians in general is “about families,” with the first movie dealing with the relationship between Quill and his mother.
Also, note how Gunn says the movie will be “about fathers,” not “about Quill’s father.” That implies there will be multiple fathers, or at least surrogate fathers, so maybe the relationship between Quill and Yondu (who basically raised him) will come up along with Quill actually meeting his literal father. Speaking of his literal father, we still don’t really know anything about who the character will be. Peter Quill’s dad is a dickish space-king named J’Son in the comics, but there’s no reason the movie has to tell the same story. Who knows, maybe Quill’s dad is Groot? After all, Guardians had a very Star Wars-y feel, and “I am your father” is only a few words off from “I am Groot.”