Ekaterina Sysoeva (Russian: Екатерина Сысоева, born 3 June 1981) is a former professional Russian tennis player.
In her career, Sysoeva won one doubles title on the WTA Tour, as well as three singles and ten doubles titles on the ITF Women's Circuit.
She reached her career-high singles rank of world No.
Her career-high in doubles is 87th, set on 14 October 2002.
Playing for Russia at the Fed Cup, Sysoeva has a win–loss 1–3.