Greg Peterson (born 26 March 1991) is a retired Australian-born American rugby union player who played lock. During his club career Peterson played professionally in Australia, Europe, and the United States. Peterson played for the United States national rugby union team from 2014 to 2024, including at the 2025 and 2019 Rugby World Cups.
Following his season with the Rays, Peterson earned a trial with Leicester Tigers and eventually signed a contract that would keep him there until the end of the 2014–15 season, but he made only a few appearances for Leicester.[4]
On 19 March 2019, Peterson returned to England to join with Newcastle Falcons in the Premiership Rugby on a two-year deal from the 2019-20 season.[10]
Peterson left Newcastle after the 2022-23 season.
[11]
He started the 2023-24 season with a short term contract with the Glasgow Warriors in the United Rugby Championship. He played the first 9 rounds of the URC and also played against Bayonne in a European Champions Cup match.
In 2024 he signed for the San Diego Legion in the MLR. In December 2024 Peterson announced his retirement from professional rugby.[12]