The ceremony took place Wednesday at the Collingswood Municipal Court.
The twice-divorced actress announced she was a lesbian just last year although it had long been known in show business circles.
McGillis, who has two children, met Leis when she worked as a bartender at a Key West, Florida restaurant the actress owned with her then-husband Fred Tillman.
McGillis has concentrated on stage work in recent years although she did appear in two episodes of the Showtime series about lesbians, The L Word.
She and Leis live near Philadelphia.
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