The 36-year-old will rejoin his former club in a new role after League One side Reading confirmed he had called time on his playing career, bringing his two-year contract to an early end.
“AFC Bournemouth has always meant a huge amount to me, so to return in this capacity is incredibly special,” Ritchie said in a statement.
“I’ve spent a long time preparing for what’s next for me after playing, learning from experienced people across the game and developing my understanding of the technical and strategic side of football.“It’s a fantastic opportunity and can’t wait to begin working with the staff, players and ownership group as we continue building for the future."
Ritchie made 142 appearances for Bournemouth, scoring 31 goals. The Scotland international also played for Newcastle United and was part of Champions League squads.