The health and skincare company called a review of its global media planning and buying business in May and the process was handled by IDComms.
The review did not include North America, which was held by J3, and was for its consumer, pharmaceutical and medical device businesses and brands.
J3 is the dedicated J&J group that Interpublic created within UM.
The global media account will now be consolidated into J3 for all its markets, including Europe, Middle East and Africa; Asia-Pacific; and Latin America (excluding Brazil).
The incumbent for the UK business is GroupM's Primus. GroupM and UM picked up the business in 2012 when it was said to be worth £200 million. GroupM created Primus within MEC to handle the account in the UK, France, Germany, Russia, Central and Eastern Europe.
UM handled the account in Spain, Italy, Portugal, the Middle East, North Africa, Pakistan and the Balkans.
A spokeswoman for Johnson & Johnson said: "When we began the review in June, our goal was to select the best agency for each region. Throughout the course of our separate regional reviews, J3 consistently demonstrated the ability to fully meet our consumer and customer needs as we drive superior growth and performance for our businesses and brands.
"Throughout the review, each of our incumbent agencies demonstrated extraordinary commitment to the process, our people and business. With this new partnership, Johnson & Johnson will continue to drive leading media capabilities and we look forward to expanding our partnership with J3 around the world."