It marks the second time that the Omnicom-owned agency has won the accolade.
Adam & Eve/DDB has been handed a haul of Lions this year including a gold, a silver and a bronze for "Trolling is ugly" for Cybersmile in Mobile; a gold and a bronze in Entertainment for "FIFA 18 More than a Game" for EA Sports, which also won a gold in Social & Influencer.
There was a gold in Creative Data for "Gene Project Case Study" on behalf of Marmite; a further gold for Marmite in Film, as well as a silver for "Personalised Cans for Father’s Day" for John Smith’s also in this category. It also won a gold and two silvers and a bronze across Media and PR respectively for "Project 84" – its male-suicide awareness campaign for Calm.
James Murphy, the co-founder of Adam&Eve/DDB, said: "To win this a second time so soon is a huge honour. The spread of work, channels and clients at the heart of this award show the value of consistent creative performance, not just one-off fireworks."
Adam&Eve/DDB was previously Cannes Agency of the Year in 2014.