Cahill was a fan favourite at Everton during his time there from 2004-12, when he made 226 appearances for the club.
“Everton Football Club can confirm that manager Marco Silva has left the club,” Everton said in a statement.
“Majority shareholder Farhad Moshiri, chairman Bill Kenwright and the board of directors would like to thank Marco for his service over the last 18 months and wish him well for the future.
“Duncan Ferguson has taken temporary charge of the first team and will manage the side for the game against Chelsea on Saturday.
“The club aims to confirm a new permanent manager as swiftly as possible.”
Silva was reported to have survived one round of emergency talks among the club’s hierarchy after the home loss to Norwich City last month but his position became untenable following defeats by Leicester City and Liverpool.
Everton conceded five league goals against Liverpool for the first time since 1982, and the Portuguese coach conceded his players had buckled under the pressure at Anfield.