Katie Jill O'Brien is a British former professional tennis player from Beverley, Yorkshire. She was briefly the British No. 1 tennis player, and reached her career-high singles ranking of world No. 84 on 1 February 2010. She won four singles and two doubles titles on the ITF Circuit.

Michaëlla Krajicek is a Dutch tennis player. She has won three singles and five doubles titles on the WTA Tour, as well as one WTA 125 doubles title, and 14 titles in singles and 22 in doubles on the ITF Women's Circuit. On 11 February 2008, she reached her highest WTA singles ranking of world No. 30. On 23 March 2015, she peaked at No. 23 in the doubles rankings.