Kevin Smith admits he is "way fat" but says that shouldn't stop him from flying.
The director and actor says a pilot ejected him from a Southwest Airlines flight from Oakland to Burbank, California, saying he didn't fit properly in a single seat.
Smith raised a stink about the incident on his Twitter page on Sunday, saying: "I'm way fat ... If you look like me, you may be ejected from Southwest Air".
Southwest said customers must be able to fit safely and comfortably in one seat or make other arrangements.
After a storm of angry online comments, the airline issued a "heartfelt apology" to Smith in a statement on its website and offered the director a US$100 voucher. Smith refused the coupon.
Smith is the director of the films Clerks and Chasing Amy and often appears in his movies as a character named Silent Bob.
Southwest and United Airlines ask large passengers to pay for an extra seat if they cannot buckle their seatbelt or put their armrests down.
In Europe, KLM-Air France was believed to be introducing a similar policy, but the airlines later denied this.