Sir Mark Aubrey Weinberg (born 9 August 1931) is a South African-born British financier. He is known for founding several financial companies including the Abbey Life Assurance Company, Allied Dunbar and St. James's Place plc.

Weinberg was born in South Africa and educated at King Edward VII School in Johannesburg. He received degrees in commerce and law from University of Witwatersrand, Johannesburg, South Africa and practised as a barrister. He later received his Master of Laws at the London School of Economics, specialising in company law, and wrote the book Takeovers and Mergers whilst there.

In 1961, he founded Abbey Life Assurance Company in London, which was one of the first companies to develop unit-linked assurance and where he formed one of the UK's first retail property funds.

In 1971, he went on to found Hambro Life Assurance, subsequently called Allied Dunbar, where he was managing director until 1983 (it is now part of Zurich Financial Services), and grew the corporation to become the largest unit-linked life assurance company in the UK, operating in the insurance broker market as well as building up a sales force. There he formed the first retail managed fund and originated the concept of the variable premium whole life policy.

He was knighted in the 1987 New Year's Honours List.

With the late Mike Wilson and Jacob Rothschild, he co-founded J. Rothschild Assurance, which became St. James's Place Wealth Management and later joined the FTSE 100.

In 2006, he became the executive chairman of Synergy Insurance Services, an innovative corporate insurance company.

Additionally, from its founding in 2005 until 2016, he was the chairman of the Pension Insurance Corporation, a company set up to provide insurance solutions for pension scheme management, in particular for defined benefit corporate pension schemes.