Reanchai Seeharwong (born 24 March 1976 in Samut Prakan) is a retired Thai sprinter who specialized in the 100 and 200 metres.

He won the bronze medal in the 200 metres at the 1994 Asian Junior Championships.

Subsequently, he finished fifth with the Asian team in the 4 x 100 metres relay at the 2002 IAAF World Cup.

His personal best times was 10.23 seconds in the 100 metres, achieved at the 1998 Asian Games in Bangkok; and 20.69 seconds in the 200 metres, achieved at the 1999 South East Asian Games in Bandar Seri Begawan.

This biographical article relating to Thai athletics is a stub.