Askew, 54, has extensive coaching experience in schools, club and representative rugby, and joins Tigers on June 1.
A Grand Slam winner as coach of England Under-19s in 2005, who also reached the World Championship semi-finals in two consecutive years, Askew has worked with many of the leading young talents in the domestic game.
As a player, Askew represented Liverpool, Lancashire, Yorkshire and England Students before embarking on a successful coaching career.
The Tigers Academy has consistently nurtured talent, with more than 30 home-grown players making first-team appearances this season. Senior internationals to come through the system include Dan Cole, Dan Hipkiss, Louis Deacon and Ben Youngs. During last summer, Tom Croft and Harry Ellis became the first Academy graduates to be included in a British & Irish Lions tour.
Academy manager Neil McCarthy said: “The Club invests a lot of time and resource in its young players and the development of players through the Academy is one of the reasons Leicester Tigers enjoy consistent success in the domestic game.
“Tosh has an impressive record in working with young players and we’re delighted he has come on board ready for the fresh Academy intake this summer.”
Askew said: “I’ve been privileged to work with some of the leading young talents in this country during my time as an RFU coach but I’m really looking forward to the opportunity to work on a day-to-day basis with Leicester’s Academy squad. The club takes talent development extremely seriously and that is the challenge for all the coaches to take on.”