Ronald Alexander Kiefel (born April 11, 1960 in Denver) is a former professional road bicycle racer from the United States. Kiefel is a seven-time Tour de France racer, Olympic bronze medalist and member of the United States Bicycling Hall of Fame.

Kiefel rode for American professional teams such as 7-Eleven, Motorola, Coors Light and Saturn. His wins included the 1985 Trofeo Laigueglia and the 1987 Tour of Tuscany.

He became the first American stage winner in a Grand Tour when he won stage 15 (from L'Aquila to Perugia) in the 1985 Giro d'Italia.

He competed in seven Tours de France, and represented the USA at the 1984 Olympic Games, where he won bronze in the team time trial with Roy Knickman, Davis Phinney, and Andy Weaver.

In 1983 Kiefel won the USPRO road championship, the time trial and the team time trial. He was also road champion in 1988. He retired from racing in 1996 and has since commentated on TV and radio for European classics and tours. He is a coach in Wheat Ridge, Colorado, vice president of Wheat Ridge Cyclery, and promotes races and rides.

In 2004, Kiefel was inducted in the United States Bicycling Hall of Fame. He and his wife, Meegan, at one time hosted a weekly AM radio show. In 2008, he and his wife Meegan had a son, Xander.