Flores sacked after miserable second go at Watford
Watford sacked Quique Sanchez Flores less than three months after bringing him back for a second spell as manager.
The Premier League club announced the decision after a 2-1 loss to fellow struggler Southampton.
Watford surrendered a first-half lead at St Mary's and remains rooted to the bottom of the table with eight points from 14 games.
In a statement issued on its official website, Watford pledged to move swiftly to install Flores' successor.
"Quique is a man of great integrity and it was clear how much he wanted to have a positive impact, but ultimately results have dictated our decision," chairman and chief executive Scott Duxbury said. "The appointment of a new head coach is imminent, and with nearly two-thirds of the season remaining, we will provide all the support necessary to make the coming months successful."
Flores, who presided over a creditable 2015-2016 campaign, only returned to Vicarage Road in September after more than three years away.
He replaced Javi Gracia after a slow start to the season but was unable to rectify poor results.
The former Valencia and Atletico Madrid boss took charge of 12 games in all competitions for two wins, four draws and six defeats, including the humiliating 8-0 loss to Manchester City.
Former Newcastle United and Brighton and Hove Albion boss Chris Hughton is rumoured to be one of the frontrunners for the Watford post.