Hayen, 46, lasted just four months in charge of Burnley and was sacked with the club sitting down in the Championship relegation zone.
Burnley have now confirmed the appointment of former Basel and CSKA Moscow boss Celestini, 50, for an as yet undisclosed number of years.
Speaking to the club’s website, Celestini said: “I look at Burnley and I see a club with big potential and players with real quality, who can help us achieve our supporters’ ambitions.
“I know the situation we are in, and I have lived it before. Our supporters deserve to see a team playing with belief from the first whistle.”
Celestini will take charge of his first game on Saturday (October 31) as Burnley welcome Portsmouth to Turf Moor.
