Clark guided Barrow to the Championship title in their first season in the division, having gained promotion from National League 2 the year previous.
The Raiders also reached the Northern Rail Cup final, where they were beaten by Widnes.
Clark has been at Barrow Raiders for the nine years fulfilling a variety of roles including Assistant Coach and Head Coach, but his main role during that time has been to increase participation levels through his community role.
Gallagher has Super League playing experience having progressed through the youth ranks at Leeds Rhinos. The utility forward has also played for Hull KR, Widnes Vikings and Rochdale Hornets and currently plays in the Championship for Batley Bulldogs.
Both coaches will begin their role with the Foundation in mid-March where they will take up the roles of Community Rugby League Coaches to work throughout the Wigan borough.
The new roles will involve working closely with local schools, community club partners and the Wigan & Leigh Service Area to increase the participation levels across all sectors of the Rugby League community. The opportunities have arisen following a partnership between the WWCF and the RFL.
Wigan Warriors Community Foundation Manager Mike Watson said: “We are delighted to welcome Tommy and Dave into the team and I’ve no doubt that they will be great additions to the Foundation. Their role will be varied and will involve working closely with our partners to help grow the sport of Rugby League, but we are confident that we have appointed two outstanding coaches who will help take our community activities to the next level.”
Speaking to the NW Evening Mail, Dave Clark said: “Working at a Super League club is the top of the pyramid for me and this opportunity to develop grass roots rugby with Wigan is one I couldn’t turn down.”
Current Barrow Head Coach Steve McCormack added: “Clarky is a good coach and a nice guy who does a lot of work in the community for Barrow. He’ll be a big loss to Barrow but it’s very exciting for him going to a place and a club like Wigan.”