‘BUFFY the Vampire Slayer” star Alyson Hannigan – who plays the gay witch, Willow, on the teen hit – is getting married.

Hannigan, 28, is engaged to former co-star Alexis Denisof, who now stars on the “Buffy” spinoff, “Angel”

Denisof, 36, who has been dating Hannigan for about four years, popped the question while both shows were on hiatus for Christmas.

Denisof, who plays Wesley Wyndam-Pryce on “Angel,” said he proposed to Hannigan during a romantic picnic stop in California’s Napa Valley wine country.

The couple plan to marry next fall, possibly in September or October, he said.