Kathleen Blake (born December 18, 1946) is an American former professional tennis player.
Blake, a California native, won the USTA Under-16s national hardcourt championships in 1962.
Before the introduction of tiebreaks, she held the record for playing the longest match in women's professional tennis, with a 12-10, 6-8, 14-12 win over Elena Subirats at Piping Rock in 1966.
Blake's best national ranking was 11th.
Her best performances in grand slams came in doubles, including a mixed doubles quarter-final appearance at the 1965 Wimbledon Championships. She was a women's doubles quarter-finalist at the 1964 U.S. National Championships and in the same tournament two years later made the mixed doubles semi-finals with Butch Seewagen.
Married to tennis coach Wayne Bryan since 1973, Blake is the mother of identical twin doubles players the Bryan brothers (Bob and Mike).