Foyth has not played for Tottenham since December last year, having fallen down the pecking order in the centre of defence. He featured just seven times for Spurs in all competitions last season.
Foyth has not made the matchday squad in any of Tottenham’s seven games this season and now heads to Spain in search of regular first team football.
Foyth could be the first of a number of temporary departures expected at Tottenham in the last days of the transfer window.
A club statement said: 'Juan Foyth has signed a new contract with the Club until 2023 and joined Spanish side Villarreal on loan for the remainder of the 2020-21 season.'
The 22-year-old Argentine joined Tottenham from Estudiantes in the summer of 2017 and has gone on to make 32 appearances in all competitions.
Villarreal hold the option of making the move permanent at the end of the season. The Yellow Submarines are third on the La Liga table with two wins, two draws and one loss in their opening five games.
Foyth has won 10 caps for the Argentina national team. Despite his lack of minutes at club level, Foyth has been named in Albiceleste manager Lionel Scaloni’s squad for next week’s FIFA World Cup qualifying games against Bolivia and Ecuador.
