In a complaint filed on Tuesday in the U.S. District Court in Los Angeles, Bengal Mangle Productions LLC said Ted is "strikingly similar" to its own teddy bear Charlie, who was created in 2008 for the screenplay "Acting School Academy" and has appeared on websites such as YouTube and FunnyorDie.
It also said "Acting School Academy" got about 1.2 million online views between July 2009 and June 2012.
"Defendants never sought nor obtained plaintiff's permission to use the Charlie character and continue to infringe the Charlie character," the complaint said.
Bengal Mangle is seeking to recoup profit stemming from the alleged copyright infringement, and halt further infringement.
Among the other defendants are MacFarlane's Fuzzy Door Productions Inc and Comcast Corp's Universal Studios, which released the movie.
MacFarlane's agent could not immediately be reached on Wednesday for comment. Universal did not immediately respond to requests for comment.
MacFarlane directed, co-wrote and co-produced "Ted," and provided the bear's voice. The movie starred Mark Wahlberg.
Released in June 2012, "Ted" grossed about $550 million worldwide, making it the highest grossing R-rated comedy. A sequel is planned for next year.
MacFarlane also created the "Family Guy," "American Dad" and "The Cleveland Show" animated television series and hosted the 2013 Academy Awards.
(Reporting by Jonathan Stempel in New York; Editing by Bill Trott)