An honors student in high school, Robert earned a bachelor’s degree from the University of Illinois, and then pursued a master’s degree in public affairs from Princeton University. After Princeton, Robert moved to Washington, D.C., where he worked in several career-defining positions in the 1970s. His job as the public affairs director for the Corporation for Public Broadcasting served as his official introduction to the television industry. He later worked as the director of communications for the D.C. office of the National Urban League, a historic civil rights and urban advocacy organization. He also worked as press secretary for a member of the United States Congress and later became vice president of government relations for the National Cable and Television Association.

In 1980, Robert had convinced John Malone, the president of Tele-Communications, Inc., to invest US$500,000 in BET, officially launching the network. Although BET started off airing for only two hours on Friday nights, it turned a profit after only five years. The network also made a splash in the U.S. media market, when it officially became the first black-controlled company listed on the New York Stock Exchange (NYSE) in 1991.

BET remained on the NYSE until 1998, when Robert—along with Liberty Media—purchased all outstanding stocks, giving him 42% ownership of the company. In 2000, media conglomerate Viacom purchased BET for a reported US$3 billion, officially making Robert L. Johnson the first black American billionaire. Two years later, Robert established the RLJ companies, a diverse portfolio of companies that includes financial services, real estate, hospitality, automotive, and gaming businesses, among others. Headquartered in Bethesda, Maryland, USA, the RLJ Companies also operate in the U.S. in North Carolina, California, and Puerto Rico, as well as in Liberia. He remained CEO of BET until 2006 and was inducted into the Global Business Hall of Fame in 2008.