Croatian football manager was dismissed on Wednesday December 16, despite his side earning an impressive 1-1 draw at Manchester City on Tuesday night.
The Baggies have only gathered seven points from 13 league games, with eight defeats.
Bilic was informed of his dismissal at 11:45am on Wednesday by Ke Xu, the chief executive, in his office at the training ground.
A club statement read: ‘West Bromwich Albion have today parted company with Head Coach Slaven Bilic.
‘Assistant Coaches, Dean Racunica and Danilo Butorovic, and First Team Coach Julian Dicks have also left the club with immediate effect.
‘The Baggies are currently 19th in the Premier League table with seven points from 13 fixtures.
‘Albion would like to thank Slaven and his coaching staff for their efforts in achieving promotion last season and wishes them all well in the future.’
However, there are reports that negotiations are ongoing between West Brom and Sam Allardyce to become Bilic’s successor ahead of Sunday’s match against local rivals Aston Villa