Yaoki Ishii (Japanese: 石井 弥起; born 29 April 1977) is a Japanese former professional tennis player.

[1] A right-handed player from Kamagaya, Ishii won the singles title at the 1998 All Japan Tennis Championships and won a further two national championships in doubles.

[2] Ishii reached a career high ranking of 207 in the world while competing on the professional tour and featured in the qualifying draws of all four grand slam tournaments.

[3] In 2000 and 2001 he was a member of the Japan Davis Cup team, winning three of his five singles rubbers.