Peter Angelos has been principal owner of the Baltimore Orioles since buying them in a New York bankruptcy court in 1993 for $173 million. He has been one of the most active owners since that time, publicly taking stands on many issues. Some have seen this behavior as being extremely intrusive and arrogant. Angelos is famous for firing manager Davey Johnson who led the Orioles to two playoff appearences in two years, and was named Manager of the Year before being fired. Also, Angelos has fired successful General Manager Pat Gillick and alienated announcer Jon Miller. One of his most well-known stands was his refusal to have his team use replacement players in 1995 when all the other teams were willing to utilize them. Finally, Angelos was strongly opposed to the moving of the Montreal Expos to Washington, DC. Angelos is guaranteed $130 million in yearly revenue, and is assured of $360 million should he sell the Orioles, in agreement to allow the Expos to move to Washington.

Angelos was the primary benefactor of the 2004 Greek Olympic baseball team. Angelos currently runs his own law firm in Baltimore.