The Thousand Guineas Prelude is a Group 2 race run under Set Weights and Penalty conditions for three year old fillies at Caulfield conducted by the Melbourne Racing Club.

The Thousand Guineas Prelude is run over 1400m. It was first run in 1965 and was won by On Point.

The Thousand Guineas Prelude is registered as the Tranquil Star Stakes named after a champion mare who won two Cox Plates.

It was over 1600m until 1990.

The Thousand Guineas Prelude was a Listed race up to 1999 then was Group 3 up to 2012 before being a Group 2 after that. The boys version is still only a Group 3.

This race was moved to Caulfield Cup Day given the Guineas itself was moved all the way to after the Flemington carnival.

Those to do the Thousand Guineas Prelude/Thousand Guineas double are Irish Lights, Miss Finland, Azzurro and Bianco Flyer.

Instant Celebrity maintained her unbeaten record to that date in winning the 2020 running very easily. While only placing in the Guineas, she would come back in the Autumn to take the G1 Robert Sangster as an older 3yo.

The Thousand Guineas Prelude was worth $300,000 in 2023.

Notable winners of the Thousand Guineas Prelude include Instant Celebrity (2020), Smart Melody (2018), Booker (2017), Gregers (2013), Irish Lights (2009), Ortensia (2008), Miss Finland (2006), Hollow Bullet (2004), Miss Pennymoney (1999), Danelagh (1998), Azzurro (1992), Bianco Flyer (1987) and As You Like It (1976).

The 2023 Thousand Guineas Prelude was won by Coeur Volante from Vivy Air and Zourion.