The 43-year-old took the reins at The Hawthorns after Darren Moore was sacked as head coach on 9 March and began brightly as he surged to three wins in a row.
Albion then lost twice, but bounced back with Saturday's 4-1 home victory over Alex Neil's Preston North End, and as such the West Midlanders said Shan deserved the opportunity to stay put for the rest of the campaign.
"He has fully earned this opportunity to take us to the end of the season," technical director Luke Dowling is quoted by the West Brom website as saying. "He has earned the support and confidence of the players who have bought into the structural and organisational changes Jimmy has introduced."
A number of reports had suggested that Preston boss Neil was in the running for the Baggies job, but the day after their game, he signed a new three-year deal at Deepdale, and in the wake of that, West Brom have given Shan their full support.
The Albion Twitter feed posted the news on Tuesday afternoon:
Here is how some West Brom faithful responded on the social media platform:
Just to make one thing abundantly clear, if Shan fails to get us promoted there will be zero blame on him, all our anger will be directed at this pathetic board/owner who are destroying the club— DOUBLEDOINK (@GREENBAYUK_) April 16, 2019
Just the 170 million at stake lads, no biggie x— Joe (@Yacxb) April 16, 2019
Respect to Shan for what he's done but lack of ambition from the owners again trying to get up as cheap as possible— WEST BROM FAN TV (@ALBIONFANTV) April 16, 2019
Can we now have the answers from Mr Jenkins on why it has taken a month to come to this decision. Was this the Plan B when Big Dave was sacked ?. We deserve answers .— Richard Downing (@rjdowning) April 16, 2019
Obvs I’ll get behind the team and Shan’s done great- but this whole process after sacking DM is a disgrace. They had literally no idea what they were going to do. You can just see em appointing AFI again in close season. #YouDontKnowWhatYoureDoing— inderjit singh (@DesiBaggie) April 16, 2019
Further proof that sacking DM was a complete and utter balls up. Farce from start to finish. No one lined up ,no clue of how to run a football club. Top brass should’ve been sacked and Lai needs to sell to someone who’ll actually give a damn about @WBA— Andy Cooper (@andy_cooper9) April 16, 2019
West Brom currently sit fourth in the Championship table on 73 points, nine adrift of second-placed Leeds United and nine clear of seventh-placed Middlesbrough with four games left.