The club announced the decision on Tuesday with the Under-23 coach expected to be in the dugout as the side take on Chelsea in the last 16 of the League Cup on Wednesday.
“Everton Football Club can confirm that David Unsworth will take temporary charge of the Everton first team, commencing with tomorrow night’s League Cup tie at Stamford Bridge,” Everton said in a statement.
While accepting the responsibility, Unsworth thanked the team’s management for the opportunity and pledged his commitment to the side.
The 44-year-old led Everton’s Under-23 team to the Premier League title last season.
A former player with the Goodison Park outfit, Unsworth made over 300 appearances to his name and is a favourite of the fans.