The agency will be charged with developing an integrated campaign to reinforce the Art Fund brand, drive membership and raise revenues. The charity is aiming to increase its membership from 80,000 to 100,000.
The search for an agency with a "media-neutral, 360-degree offering" kicked off in July and was overseen by Andrew McDonald, the deputy head of The Art Fund.
The account has been dormant for more than a year, although Partners Andrews Aldridge was behind the award-winning "wallpaper" campaign two years ago.
The fund is dedicated to helping UK galleries and museums acquire new works of art and prevent masterpieces from being sold to buyers outside the country.
MacDonald said: "I can confirm we have appointed OgilvyOne to work on our advertising and direct marketing strategy. We are very excited about working with the agency in the future.
"Our new brand identity reflects our determination to speak out in stronger tones on behalf of public collections and their visitors.
"We see the process of relaunching as an investment in the future of the organisation, one that will help us realise our mission."
The appointment does not affect The Art Fund's media planning and buying account, held by Universal McCann.