Joy, who ran the Masters Games in Dunedin for nine years and has just completed the games director role at the Special Olympics, will start fulltime next month in his role.
The tournament is scheduled to be played in May and June next year and is the second-biggest tournament held by Fifa after the World Cup.
Joy (52) said he was thrilled to get the role and it was a job which involved overseeing everything involved in the tournament in Dunedin.
Dunedin will host seven games in the tournament - six pool games and then a game in the round of 16.
Joy said his job entailed doing everything from making sure the venue was right to having the correct accommodation for teams.
The games will be played at Forsyth Barr Stadium, which will be re-named Otago Stadium for the tournament.
''One of the key factors in my role is getting people to go to the game. So that promotion side is very important. We want to create a bit of buzz around the tournament and get people talking about it,'' Joy said.
''Hopefully, we can tap into football clubs here, Football South, use all the networks which are out there.
''The good thing we have is that we have three double-headers. The times have not been finalised yet but by playing double-headers it makes it more attractive for people to come.''
Fifa will decide the ticket prices later in the year and qualifying matches will be played throughout this year.
The venues will have no say in what teams will play where, although New Zealand, which has qualified already as host country, will not play a game in Dunedin.
Joy said it would be a good standard of football and there was the chance to see some top-quality players, who were already playing in major leagues around the world.
Supporters would also come from around the world to follow their teams, which should be an economic boost for the region, Joy said.
The most recent under-20 World Cup was played in Turkey last year and was won by France. New Zealand lost its three games at the tournament.
