Mason leaves the club 18th in the Championship having won just four of their last 16 matches as fears of relegation grow amongst supporters who will be happy to see Mason depart.
This was the 34-year-old’s first full-time managerial gig, and his departure comes less than 24 hours after West Brom were beaten 2-1 at Leicester on Monday.
The defeat was West Brom’s 10th straight away defeat, which is the worst run in club history. Mason’s departure was announced by the club on Tuesday morning in what was a brutal decision.
“West Bromwich Albion have today parted company with men’s first team Head Coach Ryan Mason.
“The club would like to place on record its thanks to Ryan, Nigel and Sam for their efforts and wishes all three the very best for the future.
“First Team Coach James Morrison will oversee first-team affairs on an interim basis until a new staff is appointed.
“The process of recruiting a new men’s first team Head Coach and staff is under way.”
West Brom’s next league fixture is on Friday as they host Middlesbrough, who are 16 places above them.