The Socceroos legend will lead the club's young players into their first season in the Under-21 Professional Development League Two South.

UNDER-21: #watfordfc is pleased to confirm the appointment of Harry Kewell as Under-21 Coach http://t.co/CB0lajdKnK pic.twitter.com/HDPgvxTwl8 — Watford FC (@WatfordFC) July 23, 2015

Kewell, played 56 times for Australia, brought the curtain down on his playing career last year following a brief stint at Melbourne Heart, and the new role at Watford represents his first step into coaching, although he has established a youth academy in Australia.

"We are delighted that Harry has agreed to join us as our new Under-21 coach," sporting director Luke Dowling said.

"Harry enjoyed an extremely successful career as a player, and he now has a proven track record when it comes to working with and nurturing gifted young footballers.

"His knowledge and experience will be of great benefit to the club's youth set-up as a whole, and the talented players we have within our Under-21 group."

Kewell was part of the Liverpool team that won the UEFA Champions League in 2005.