Nicolas Kiefer
- Date of birth: July 5, 1977
- Birthplace: Holzminden, Germany
- Residence: Sievershausen, Germany
- Height: 6'0'' (1.82 m)
- Weight: 177 lbs (80 kg)
- Plays: Right-handed
Nicolas Kiefer won a silver medal in men's doubles with partner Rainer Schuttler at the 2004 Summer Olympics in Athens.
Kiefer was taken notice of as an outstanding junior. He won the Junior Australian Open, US Open and was a finalist and semi-finalist at Wimbledon and the French Open finishing as the number 2 junior behind Zabaleta when he was 18.
On 10 January 2000, he reached his second quarterfinal at the Australian Open and afterwards was ranked World No. 4, his highest position to date.
