The process was handled by the AAR. The account is worth £10 million.
In March, Campaign revealed Carpetright was on the hunt for an agency.
Helen Vinken, the marketing director at Carpetright, said: "We are delighted to be partnering with Different at this exciting time of change for the Carpetright brand.
"It was the right time to review our creative account and the quality of strategic and creative thinking we have seen throughout the review has been superb."
Different has worked on the business since 2013. Ben Quigley, the chief executive at Different, said: "There are ambitious plans to take Carpetright to the next level with the brand right at the epicentre."
The carpet retailer appointed Twenty20 Media Vision to the £8 million non-broadcast media and creative accounts for the Carpetright and Sleepright brands in March 2010. However, the agency no longer held the account when it was closed earlier this year.
It hired the Kent-based agency WFCA to handle the business in 2004. WFCA was later integrated into Twenty20 Media Vision.
Carpetright has an estimated 600 stores across the UK, the Netherlands, Belgium and Ireland. More than 400 of the stores are in the UK.
Lord Harris of Peckham founded the first store in Canning Town, London, in November 1988.