The longtime girlfriends will say "I do."

ELLEN DEGENERES and PORTIA DE ROSSI are set to tie the knot!

The celebrated talk show host and her long time girlfriend will make the announcement on Ellen's show today, an audience member told the Associated Press press after yesterday's taping.

The big news comes on the heels of the California high court striking down state laws against gay marriages.

Ellen herself spoke out to The Advocate, saying, "I'm thrilled that the California supreme court overturned the ban on gay marriage. I can't wait to get married. We all deserve the same rights, and I believe that someday we'll look back on this and not allowing gays to marry will seem as absurd as not allowing women to vote."

She added, "P.S. I'm registered at Crate & Barrel."