Simpson was facing an uncertain future at Lathlain Park despite being contracted until the end of 2025, with the Eagles recording the second wooden spoon in their history through a three-win season.
West Coast have managed just five wins over the past two years, with the club's list turning to the future amid a period of transition.
During the time of change, calls for the Eagles to part ways with Simpson were growing, however, for the second time this year, the club's board has released a statement of support for its embattled coach.
Eagles Chairman Paul Fitzpatrick said on Monday that the club is supporting Simpson, who is viewed as the man to lead the club through the coming years despite the recent struggles.
“At the meeting today the Board unanimously agreed that Adam will remain as senior coach,” Fitzpatrick said in a club statement.
“No one knows our playing list better than Adam and he has already steered us through the first phase of the rebuild. We are confident he can take us forward and take us where we aspire to be.
“Our season came to an end on Saturday night and we finished at the foot of the premiership table. That does not sit well with anyone at the club and we are all aware that there is much work to be done to return as a force in the competition.
“While this season has been challenging I would like to again acknowledge our members and fans for their loyal support of the club. To have 47,000 at Optus Stadium again on Saturday was quite remarkable and provided a wonderful backdrop to farewell three West Coast Eagles champions.
“I would like to acknowledge the extraordinary contributions of Shannon Hurn, Luke Shuey and Nic Naitanui over almost two decades. If we needed a reminder that this is the start of a new era it came through the post-match celebrations of these stars of our club. They are legends in every sense.
“Some of the work that is required to improve has already started and it will continue in the off-season and through the pre-season. We know we need to be better across all aspects in the football program.
“We will again go to the draft where we currently hold the first selection and we will look to bring in some elite youngsters with that and other selections.
“We are also open to bringing in players through the trade period who fit our needs and list profile.
“Adam is central to our development plans to assist the club's rise up the ladder.”
Simpson has won 106 of his 226 games in charge of the Eagles, including the 2018 Grand Final.