Faloon will replace Richie Murphy, who has been confirmed to take over as Ulster boss on a permanent basis.
Faloon had been Ireland Under-20s defence coach under Murphy for the last two Six Nations campaigns, as well as last year’s World Cup.
Ian Keatley (attack and backs) and Aaron Dundon (forwards) will continue in their current roles, while Neil Doak adds a wealth of coaching experience to the set up as he joins as a senior coach.
Doak, father of Ulster scrum-half Nathan, has coached the Ireland Under-18s and Combined Academies in recent seasons following spells with Ulster, Ireland, Worcester and Georgia.
This year’s Junior World Cup will be played over five match days – between June 29 and July 19 – in Stellenbosch and Cape Town, with World Rugby due to announce the pool schedule at the end of this month.
In advance of their departure for South Africa, the Ireland U-20s will play three challenge matches against Irish Universities (May 24), Ulster ‘A’ (June 1) and Munster ‘A’ (June 7).
“We would like to firstly congratulate Richie on his new role with Ulster,” said IRFU head of elite player development Peter Smyth.
“He has done an exceptional job with the Ireland Under-20s in recent seasons and on behalf of all the management and players, we wish him well for the remainder of the season with Ulster and beyond.
“It was important for us to maintain consistency within our group so we are pleased to confirm the appointment of Willie as Ireland U-20s head coach for this summer, with Aaron and Ian continuing in their roles and Neil joining the team as a Senior Coach.
“A World Rugby U-20 Championship is always an exciting challenge and coming off the back of the Six Nations, the group are motivated to work hard in the weeks ahead to put themselves in the best position to perform against the world’s best in South Africa.”
Ireland U20s Coaching Team – 2024 World Rugby U20 Championship
Head coach – Willie Faloon
Senior coach – Neil Doak
Attack and backs coach – Ian Keatley
Forwards coach – Aaron Dundon