Alexander Brown, was an Irish merchant and banker. Beginning as a merchant trader, first of linen in Belfast, then of cotton and tobacco after migrating to Baltimore, Maryland, he later shifted his focus to financial services. He founded Alex. Brown & Sons, the oldest investment banking firm in the US, in 1800, and with his sons operated a network of banks in the US and England. He made his fortune from the transatlantic cotton trade, and was one of the first millionaires in the United States.

Alex. Brown & Sons was the first investment bank in the United States, founded by Alexander Brown in 1800 in Baltimore, Maryland. The firm was acquired by Bankers Trust in 1997 to form BT Alex. Brown, and then integrated into Deutsche Bank in 1999 following Deutsche's acquisition of BT. In 2016, Raymond James acquired Deutsche's U.S. private client services unit, operating under the Alex. Brown brand.