Spoilers ahead for Guardians of the Galaxy plot details. When the topic came up about Star-Lord's father, James Gunn stated in an interview with Empire, "It’s definitely not the character who it is in the comics, I’ll say that much."
According to what was said in the interview, only four people involved with the Guardians of the Galaxy production team know who Peter Quill's father will be in the Marvel Cinematic Universe: James Gunn, Kevin Feige, Michael Rooker, and Sean Gunn.
Based on tidbits of information from the movie, the comics, and James Gunn's own comments, who do you think will be Peter Quill's father in the Guardians of the Galaxy sequel? Is James Gunn simply trying to throw Marvel fans off the scent? Moreover, of the names that seem to float around out there often as likely candidates to have hooked up with Peter's mom, who would you be inclined to tell in Maury Povich like fashion, 'You are NOT the father'.
http://www.ranker.com/list/guardians-of-the-galaxy-2-star-lord-i-am-your-father-/switchdoctor,
Adam Warlock
Black Bolt
Captain Marvel (Mar-Vell)
Starfox
Thanos
Eternity
Odin
Starhawk
Loki
Vance Astro