Aston Villa have "parted ways" with manager Dean Smith, the Premier League club announced on Sunday.
Smith, who was in charge at Villa for three years, leaves with the club 15th in the Premier League table after five successive defeats.
"Aston Villa Football Club can confirm that the club have parted company with head coach Dean Smith," Villa said in a statement.
Smith joined Villa in October 2018 and led the club to promotion to the Premier League via the Championship playoffs. He guided Villa to safety in 2019/20, finishing one place and one point above the relegation zone, and led significant improvement last season as the club finished 11th. Smith also led Villa to the League Cup final in their first season back in the top flight.
Villa entered this season having to contend with the British record sale of captain and star player Jack Grealish to Manchester City, although the club recruited well to strengthen the squad.
However, after an encouraging start to the campaign, Villa's form has nosedived and Smith leaves with the club two points above the drop zone.
“When Dean joined us in October 2018 our team was really struggling in the Championship. He immediately transformed the atmosphere and performances and achieved the ultimate success of leading Villa back to the Premier League within the same season - a rare feat," Villa chairman Christian Purslow said.
"He then secured our place in the Premier League after a tough campaign and took us to a Cup Final at Wembley.
"However, after a good start to last season, this year we have not seen the continuous improvement in results, performances and league position which we have all been looking for. For this reason we have decided to make a change now to allow time for a new head coach to make an impact.
"The Board would like to sincerely thank Dean for his many excellent achievements, on and off the pitch, during this time. Everyone knows how much Aston Villa means to Dean and his family.
"He has represented the Club with distinction and dignity - universally liked and respected by everybody associated with Aston Villa – our staff, players and supporters alike. We wish him the very best.”
Villa announced that their search for a new manager is underway.