Baggies head coach Steve Clarke confirmed last week that Albion have opened talks over a new contract with McAuley, who has 15 months to run on his current deal.
Olsson admits his partnership with McAuley was a key factor in him signing a new contract earlier this season.
The Sweden international said: "It is vital to keep Gareth. We have formed a good partnership over the past couple of seasons.
"When I signed my new contract, one of the big reasons was that I enjoy playing alongside him so much.
"For me it is vital that we keep him."
Olsson pinpoints Albion's ability to retain the services of key players as a major factor in establishing themselves in the Premier League. He said: "Continuity has been important at Albion, keeping players.
"People like James Morrison, Graham Dorrans, Chris Brunt, Steven Reid and Youssouf Mulumbu have been here for a while now.
"That experience, and being able to keep those good players, has been a key factor.
"Albion haven't lost too many players they didn't want to lose."