René Kalmer (born 3 November 1980 in Roodepoort, Gauteng) is a South African runner who has competed over distances ranging from 800 metres to the marathon.

She was the silver medallist at the FISU World University Cross Country Championships in 2002, finishing behind Denisa Costescu.

She represented South Africa at the 2008 Beijing Olympics in the women's 1500 metres, although she did not progress past the first round.

Domestic success came outdoors soon after as she won the 1500 m and 5000 metres races at the South Africa Senior Track and Field Championships, saying her marathon run had greatly increased her stamina.

The Yokohama Women's Marathon in November saw her further improve her times as she dipped under the two-and-a-half-hour mark, coming fifth in 2:29:59 hours.