Mitchell was working as Southampton’s head of recruitment and scouting before the 33-year-old reportedly handed in his notice earlier this month.
Spurs manager Mauricio Pochettino worked with Mitchell during his 15-month spell in charge of Southampton.
A Tottenham statement read: “We are delighted to announce that Paul Mitchell has joined the club as Head of Recruitment and Analysis.
“A former player with Wigan Athletic and MK Dons, Paul initially took up the role of Community Ambassador with the Dons when he retired from playing in 2009 at the age of 27.
“Following the appointment of Karl Robinson as manager in 2010, Paul was assigned to his back room staff as Head of Recruitment, recognising his aptitude for identifying player talent.
“He joined Southampton in January, 2012 to manage their Scouting and Recruitment department.”
Southampton have been praised for the signings of Graziano Pelle, Dusan Tadic, Sadio Mane and Toby Alderweireld this summer.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news