The 43-year-old Dane arrives in North London following a three-year spell at Villa Park, where he helped to oversee the Lions' transition from a bottom-half side to a Europa Conference League competing team.
Lange spent three years as Villa's Sporting Director between 2020 and 2023, during which time the Lions sealed the marquee captures of high-profile players such as Philippe Coutinho, Ollie Watkins, Emiliano Martinez and Emiliano Buendia.
Lange was promoted to Villa's Global Sports Director this summer, but he has left that role after only a few months to join Tottenham, where he will be responsible for "recruitment, analytics and talent identification" at senior and academy level.
"Johan has demonstrated an excellent track record of scouting and signing many talented and successful youth and senior players. He is a welcome addition as we strengthen our football operations," Tottenham's Chief Football Officer Scott Munn told the club's website.
Prior to joining Villa, Lange held a variety of roles with FC Copenhagen, serving as their academy manager, assistant first-team manager, technical director and director of development.
The 43-year-old also spent 22 games in charge of Lyngby BK after a brief stint as Wolverhampton Wanderers assistant under Stale Solbakken from July 2012 to January 2013.