Marshall was handed temporary control of first-team affairs at the Premier League strugglers following last week's sacking of manager Paul Lambert.
However, with Tim Sherwood having been swiftly appointed as the permanent successor to Lambert, Marshall has now exited Villa Park.
A brief statement from the Midlands club read: "Aston Villa have parted company with first-team coach Scott Marshall."
Villa chief executive Tom Fox added: "I'd like to thank Scott for his efforts during his time at the football club and especially under difficult circumstances at the weekend when he took the team for Sunday's FA Cup victory over Leicester City.
"We wish him all the best in the future."
Villa sit 18th in the Premier League and host Stoke City on Saturday.
