Casey Anthony clearly has daddy issues ... which means she'd make a GREAT porn star ... and TMZ has learned she's already received an offer from the biggest name in the biz.

Hours after she was found not guilty of murdering her 2-year-old daughter Tuesday, Vivid Entertainment honcho Steve Hirsch called up Casey's lawyer, Jose Baez, to discuss the possibility of a business relationship.

Hirsch tells TMZ ... "Whether you agree with the verdict or not, Casey will want to move forward with her life and has a right to make a living. It’s not going to be easy for her and we believe we can help her make the transition into a new life."

No word on how much Hirsch is willing to pony up ... but he thinks there's a realistic chance ... noting, "We’ve all seen the pictures of her partying and having a good time with friends where she definitely looks hot."