The 20-year-old will go straight into manager Simon Grayson’s squad for the clash with Burnley.
Grayson told the club’s official website: “Andros is a quality young player with proven experience at this level and we’re delighted to be able to bring him to Leeds.”
London-born Townsend, who joined the Tottenham academy as a nine-year-old, has represented England at U-16, U17 and U19 level and has had previous loan spells at Yeovil, Orient, MK Dons, Ipswich, Watford and most recently at Millwall, for whom he made 11 appearances at the end of last season.
Townsend has featured for Spurs six times in the Europa League this season and also against Stoke in the Carling Cup.