The 39-year-old, an assistant to Marcelo Bielsa at Elland Road, appeared to be the favourite to replace the sacked Jesse Marsch but has instead committed himself to The Hawthorns until the summer of 2027.
"I believe that success can only be achieved when everyone works together and the way I have been made to feel welcome at this great club has made me confident that this is the right place for me," said Corberan, who has won 10 of his 13 matches in charge to take the relegation-threatened Baggies into sixth in the Sky Bet Championship.
"It is important to me that we do not let this moment distract us from our target, which is to ensure we improve every day, making the team more and more competitive for the challenges ahead."
Corberan only signed a two-and-a-half-year contract in October after taking over from Steve Bruce with the team struggling near the foot of the table.
However, the Spaniard's impact has been so impressive he started talks with chief executive Ron Gourlay three weeks ago about where the club was going and that has prompted the contract extension.
"I have always been impressed by Carlos and my admiration of him as a coach has only grown since he arrived here," said Gourlay.
"His passion for the game we all love has been infectious for all connected with the club, not least our players, who have clearly benefited from Carlos' first-class coaching, tactical know-how, and attention to detail.
"We sat down three weeks ago to discuss the future of the club and Carlos' vision for Albion is absolutely aligned with my own.
"Together we are determined to continue taking the club forwards."