The free agent signed a two-year contract running to June 2028, becoming Deportivo's eighth arrival of the summer as the club completes its squad ahead of a return to the top flight.
Traoré, born in L'Hospitalet de Llobregat, arrived at Santiago airport having flown from Barcelona, where he had been based since his contract at West Ham expired, and could train at Abegondo as soon as this week if head coach Antonio Hidalgo deems it appropriate.
The move ends Traoré's long association with the Premier League, where he built his career across spells at Aston Villa, Middlesbrough, Wolverhampton Wanderers, Fulham and, most recently, West Ham United, amassing more than 270 appearances in England.
He also spent a loan spell back at Barcelona in 2022. A Barcelona academy product, he had initial reservations about returning to Spain and had been seeking wages that complicated negotiations, but those obstacles were resolved in the past few days to make the deal viable.
Right wing has been Deportivo's clearest priority in the closing stretch of the window, a position filled so far this season by Adrià Altimira, a full-back Antonio Hidalgo repurposed further forward last term following David Mella's injury.
Traoré's arrival effectively exhausts Deportivo's wage budget for the summer, leaving the club with little room to pursue the central defender it had also been targeting, though sporting management have not ruled out squeezing in one more addition before the deadline if the numbers allow it.
Traoré joins a rebuilt squad that already includes Angeliño, Pierre-Emerick Aubameyang, Giovanni Amatucci, Ivo Gijselhart, Jensen, Leo Román and Ede, giving Deportivo a mix of youth, experience and proven quality as they prepare for life back in LaLiga.
His arrival closes a saga that had rumbled on for weeks, with Deportivo choosing not to wait until the final day of the market to complete the piece Hidalgo had identified as his squad's biggest attacking need.