Claudia Ștef, née Iovan (born 25 February 1978 in Craiova, Romania) is a Romanian race walker.
Ștef holds the world indoor record for 3000 metres track walk with 11:40.33 minutes, achieved in January 1999 in Bucharest.
She tested positive for nandrolone in an out of competition test 20 May 2000 and received a two-year doping ban.