Olsson, 34, would have been out of contract in the summer, but has reached a mutual agreement with Albion to terminate remaining months of his deal.
2016 SeasonAll times ET
The West Brom midfielder has returned to the England squad after escaping a two-year suspension in 2015 following a positive test for cocaine.
Despite having only 23 percent possession, nobody could argue that Tony Pulis' team were the better side in a 3-1 win over Arsenal.
Tony Pulis believes West Brom should be proud of their Premier League campaign regardless of what happens in the remaining nine matches.
If Arsene Wenger is to finally leave Arsenal this summer, the next 11 league games will have a huge bearing upon the fans' mood when he says goodbye.
There were dueling plane banners both for and against Arsene Wenger as West Brom beat Arsenal 3-1 to pile pressure on the Frenchman.
Arsenal's top-four hopes suffered another blow as they lost 3-1 to West Bromwich Albion at the Hawthorns.
West Brom head coach Tony Pulis believes Arsenal boss Arsene Wenger is years away from quitting management.
Manchester City and Arsenal are both coming off the back of embarrassing European exits, while the Chelsea machine may keep rolling on.
Jonny Evans and West Brom were pushed around by Romelu Lukaku and Everton, as WBA looked no match for the team one spot ahead of them in the table.
|West Bromwich Albion||29||12||7||10||+1||43|
|West Ham United||29||9||6||14||-12||33|