The club confirmed the extension in a statement on Thursday, four days before Deportivo's return to the top flight for the first time in eight years.
"The continuity of the coaching staff represents a commitment by the club to stability and the consolidation of a project that continues to grow, giving continuity to the work already begun and to an idea of team that allowed Dépor to reclaim its place among the best," the statement read.
Sporting director Fernando Soriano and chief executive Massimo Benassi both signed off on the extension, which ties Hidalgo to the Riazor club for two more seasons beyond the current one.
The Catalan coach, born in Granollers in 1979, arrived last summer from Huesca, where he had spent a season and a half, and delivered an immediate return to the top flight by winning automatic promotion rather than having to negotiate the play-offs.
"This extension reinforces a line of work based on trust and growth, with Hidalgo as one of the fundamental pieces of the sporting project," the club added.
Hidalgo, who turns 48 in February 2027, will take charge of a top-flight team for the first time in his coaching career when Deportivo begin the season, having overseen a solid pre-season that brought just one defeat in seven friendlies — a 1-0 loss to Real Madrid in the Trofeo Teresa Herrera.
As a player, Hidalgo spent time at Real Zaragoza, Osasuna, Sabadell and Cornellà before moving into coaching, a background that has shaped his reputation for building organised, hard-working teams.
Deportivo La Coruna's rise back to the top of Spanish football ends an eight-year absence and follows a lengthy period of reconstruction after their relegation from La Liga in 2018.
The renewal is intended to send a message of stability at a club aiming to consolidate its return without sacrificing its growth, with Hidalgo now facing the challenge of keeping Deportivo in the division while continuing to build on the progress made during last season's promotion campaign. The club are keen to carry the momentum of that positive pre-season, in which they lost just once in seven outings, into the opening weeks of the new season, with the fixture list set to test that early promise from the very first weekend.