Hailing from the United Kingdom, Louis Foster is the son of former British Touring Car Championship (BTCC) driver, Nick Foster.

After moving to the US in 2022, he immediately showcased his potential by winning the Indy Pro 2000 Championship, a development category of the INDYCAR SERIES. In the subsequent 2023–2024 seasons in INDY NXT by Firestone, he demonstrated dominant performance, achieving an impressive 10 pole positions and 10 victories over two years to claim the title.

Carrying this momentum, he stepped up to the INDYCAR SERIES in 2025. In his rookie year, he secured one pole position and concluded the season 23rd overall.