Roger Nathan Dahlberg (22 February 1965 – 22 August 2024) was a New Zealand racing cyclist. He rode in the Tour de France in 1988 and 1989 and was 39th in the 1990 Giro d'Italia. Dahlberg spent his career being a domestique for other riders and occasionally being allowed to race for himself.

After retiring from racing Dahlberg managed the Marco Polo Cycling–Donckers Koffie until it folded in 2012. In 2015 he set sights on the world record for highest elevation cycled. He chose Broad Peak as the place for this attempt as it provided flat enough terrain to ride the required 20m for the record. While he was hiking up the 12th highest mountain in the world he slipped on some ice and fell down the hill but was able to use his ice pick to stop himself. He survived with just a head cut but lost his passport and other valuables. His team abandoned the expedition at the second camp as conditions were unsuitable for the attempt.

Dahlberg died in China on 22 August 2024, at the age of 59.