Ernesto Valverde has been sacked by Barcelona after two-and-a-half years at the Nou Camp, with Quique Setien taking over until June 2022.
Valverde is the first manager to be sacked by Barcelona mid-season since Louis van Gaal was dismissed in January 2003.
Barcelona are currently ahead of Real Madrid at the top of La Liga on goal difference, but were knocked out in the semi-finals of the Spanish Super Cup on Thursday after a 3-2 defeat to Atletico Madrid.
They are through to the Champions League knockout stages, where they will face Napoli in the Round of 16 in February.
Valverde, previously at Athletic Bilbao and Valencia, replaced Luis Enrique in 2017 and won back-to-back league titles during his time in charge.
He released a statement on the Barcelona website on Tuesday morning.
It read: "My time as FC Barcelona coach has come to an end. It has been an intense two-and-a-half years right from the start. In that time I have enjoyed some joyful moments celebrating victories and trophies but also others that have been tough and difficult.
"However, above all, I would like to highlight my experience with the fans and the affection showed towards me during my time as coach.
Valverde at Barca (joined May 2017)
|Honours||La Liga x 2, Copa del Rey, Spanish Super Cup|
"I would like to thank the president Josep Maria Bartomeu and the Board of Directors for giving me the opportunity to coach the first team and their confidence during all this time.
"I would also like to thank all the people I have worked with at the club for their support and how they treated me during the two and a half seasons, especially those who work in and around the first team and with whom I have shared so many moments at the Ciutat Esportiva and during away trips.
"Of course, I would like to thank the players for all their efforts that have allowed us to claim four trophies together. From this day, I wish them all the luck in the world and to the new coach Quique Setién also."
Setien, 61, has had recent success in La Liga, guiding Las Palmas to survival in 2015, before taking Real Betis into Europe in 2018.
He led Betis to wins over Barcelona, Real Madrid and Atletico Madrid last season, but was sacked at the end of the campaign.
Former players Xavi and Ronald Koeman were approached by the club to take over from Valverde this month, but both turned down the opportunity.
Reports suggested that Xavi, who is currently in charge at Qatari side Al Sadd, was prepared to take the job at the end of the season, but the Spanish champions decided to opt for an immediate appointment.