Tomokazu Ohka (?? ??, Oka Tomokazu, IPA: [o?ka tomokaz?]) (born March 18, 1976) is a Japanese former professional baseball pitcher.
He played for the Boston Red Sox (1999–2001), Montreal Expos (2001–2004), Washington Nationals (2005), Milwaukee Brewers (2005–2006), Toronto Blue Jays (2007), Cleveland Indians (2009), as well as the Fukushima Hopes in Japan's Baseball Challenge League.
He started his professional career with the Yokohama BayStars in Nippon Professional Baseball's Central League.