Antoni Niemczak (born 17 November 1955) is a retired long-distance runner from Poland, who won the inaugural 1984 edition of the Vienna Marathon, clocking 2:12:17 on March 25, 1984.
He finished in eighth place at the 1986 European Championships in Stuttgart, West Germany.
[1] Niemczak tested positive for the anabolic steroid Nandrolone after finishing second at the 1986 New York City Marathon.
,[2] Niemczak received a two-year suspension from the sport.
This biographical article relating to Polish athletics is a stub.