Billie Jean King to join Jill Biden to mark Title IX’s 50th anniversary

Billie Jean King and Jill Biden are teaming up to mark the 50^th anniversary of Title IX at a celebration in Washington.

The first lady and the tennis champ’s participation in the Wednesday event at Capitol One Arena was announced Tuesday by the White House.

Title IX, the federal civil rights law that prohibited sex-based discrimination in educational programs that receive federal financial assistance, was signed on June 23, 1972.

Seventy-eight-year-old King — who famously won the 1973 “Battle of the Sexes” match against Bobby Riggs — has been a longtime gender equality advocate.

It’s not the first time that King has championed Title IX at an event tied to 1600 Pennsylvania Ave. The 39-time Grand Slam champion also marked the 40^th anniversary of Title IX back in 2012 as part of a star-studded panel hosted by the White House Council on Women and Girls.

The Wednesday gathering will also recognize the 10^th anniversary of the State Department’s global sports mentoring program, according to the White House. Biden, King and a soon-to-be college track athlete are all expected to deliver remarks at the Title IX anniversary ceremony.