The ethnic festivals will be out in force this weekend.

* The Japan-America Society will hold its annual Japanese festival and bazaar this Saturday on the campus of Mount Vernon College. There'll be lots of Japanese crafts, food and clothing on sale. Martial arts demonstrations, live Japanese music and folk dancing will round out the day. Hours are 11 to 4. A $2 donation is requested; free for those under 16. Mount Vernon College is on Foxhall Road NW between Whitehaven Parkway and W Street. 289-8290.

* Sons and daughters of Ireland still smarting over the Celtics' big loss can salve their psyches at the Irish Festival in Old Town Saturday. Live Irish music and dance will be on tap; arts and crafts will be on sale. It's from 11 to 6, at Market Square in the 300 block of King Street. 838-4343; free.

* The weekend-long Italian Festival in Annapolis has gotten so big that they've had to move it outdoors this year to the Navy- Marine Corps Stadium. Opera singers, mandolin players, folk dancing and a magic show are on the bill, and there'll be enough pasta on sale to satisfy the biggest of bellies. Hours are 12:30 to 11 p.m. Friday and Saturday, 11 to 8 Sunday. It's free; parking costs $1. To get there, take U.S. 50 to Rowe Boulevard and follow it to the stadium. 301/647-1986.