ONAR Holding Corporation operates as a marketing technology company and agency network in the United States. It operates through Advertising and Marketing Services and Healthcare Marketing segment. The Advertising and Marketing Services segment provides digital marketing, creative, data science, and technology services. The Healthcare Marketing segment offers healthcare marketing solutions, specializing in medical laboratory and genetic testing marketing. The company was formerly known as Reliant Holdings, Inc. and changed its name to ONAR Holding Corporation in February 2025. ONAR Holding Corporation was incorporated in 2014 and is based in Miami, Florida.