Peter G. Peterson, the billionaire financier and philanthropist who combined a spectacular career in industry and Wall Street with public policymaking and dogged advocacy of government fiscal prudence, died on Tuesday at his home in Manhattan. He was 91.

His family confirmed the death in statement.

Mr. Peterson was one of the few captains of business whose reach extended into the public sphere. Forbes magazine described him as having “one of the most distinguished résumés in America.” He was secretary of commerce under President Richard M. Nixon, led government commissions and advisory bodies and for 22 years was chairman of the influential Council on Foreign Relations in New York, succeeding the banker David Rockefeller, who died last year, also on March 20.

As a fiscal watchdog, he created a well-financed foundation that addresses a spectrum of fiscal issues and holds conferences that draw America’s top financial and political leaders.

He wrote a half-dozen books laying out his vision for economic prosperity while critiquing, and criticizing, entitlement spending, the Social Security system and the impact on the economy of partisan politics in Washington.