Mediahub is a global media planning and buying agency that launched in 2005 as a media unit of IPG-owned Mullen and later operated inside IPG Mediabrands. After Omnicom completed its acquisition of Interpublic on 26 November 2025, Omnicom Media combined Mediahub with Hearts & Science on 28 August 2026 to create Hearts United, a New York–headquartered media agency that operates in 40 markets and reported about $9.1 billion in 2025 billings. The official Hearts United site says it works with more than 80 clients and names Nicole Estebanell as U.S. CEO and Ross Jenkins as EMEA CEO, both formerly Mediahub regional leads; the historic mediahubww.com homepage now redirects there.