The agency won the pitch, which kicked off in January, in a final shoot-out against Proximity London. The business was previously handled in-house.
The appointment does not affect the retailer's creative account with MWO, which has handled the business since 2008.
PAA will be responsible for handling the digital and direct marketing activity for the brand, focusing mainly on promoting and improving Wickes' My Wickes Card loyalty programme.
The appointment comes as Wickes shifts its focus beyond in-store promotions to reach a mass audience. At the beginning of the year it launched a series of television spots to promote the variety of products on offer in its catalogue for the first time.