Actress Leisha Hailey -- who starred in "The L-Word" -- says Southwest Airlines hates gay people ... and claims that's the reason she got kicked off a flight today.
Leisha just unleashed a flurry of tweets to her thousands of followers -- claiming a flight attendant booted Leisha and her GF for kissing on the plane ... because SW is a "family" airline.
Leisha is now demanding a public apology from Southwest -- calling for her fans, and gay people everywhere, to boycott the airline for its "homophobic" policies, writing, "They don't like us."
A rep for Southwest tweeted her back with a quick apology -- asking for Leisha to contact the company privately so they can sort out a solution. So far, no official word from Southwest.