Roach and Fletcher replace Shaun Brooks and Paul Groves, who left their posts in the Cherries Academy last week, and Howe is pleased to have appointed two individuals familiar to the club.
“We are delighted to bring them both back and I think it is a really positive appointment for the club’s long-term future," he said. "They know the club very well and I don’t think we could have got two better guys.
"We are getting two Bournemouth people who will work incredibly hard for the benefit of the players."
A product of the Cherries youth system himself, Fletcher rejoins the club he left in 2003 for spells at West Ham United, Crystal Palace and Plymouth, where he also spent 15 months in management.
Roach, who oversaw the development of a host of youngsters including Sam Vokes and Danny Ings, returns to the Goldsands Stadium after two-and-half-years of putting his knowledge of the game to good use, working in various capacities at youth level.
"All you can ask from any coach is to try to improve players day in, day out and I know they will," Howe added. "The rest then will be up to the players to take their careers further once they leave the youth ranks.
"We have asked them to give the current players within the system every chance to progress into the first team and, if not with us, then hopefully to the best level of their ability."