The Thorndon Mile is a Group 1 race run under set weights and penalties conditions for milers at Trentham race course conducted by the Wellington Racing Club.

The Thorndon Mile is run over 1600m. It was first run in 1962 and was won by Starborough.

The Thorndon Mile is part of the Wellington Cup carnival in early January.

It has always been run over the mile but was known as the George Adams (Tattersalls) Handicap. It became the Thorndon Mile in 1984.

Rosie Myers has won 3 of the last 15 editions joining David Walsh, Lance O'Sullivan and Opie Bosson.

Noel Eales won five runnings between 1990 and 2001.

Both Alamosa and Wall Street won G1 miles in Melbourne later in the years of their Thorndon success.

Melody Belle equalled the great Sunline's record for a NZ trained horse of 13 G1s by winning in 2021.

The Thorndon Mile was worth NZ$500,000 in 2025.

Notable winners of the Thorndon Mile include The Chosen One (2022), Melody Belle (2021), Kawi (2016), Wall Street (2010), Sir Slick (2007/2009), Alamosa (2008), Giovana (2002), Pace Invader (2000), Fayreform (1998), Calm Harbour (1993), Fire Commander (1991) and McGinty (1983).

The 2024 Thorndon Mile was won by Puntura from El Vencedor and Lady Telena.