William Warren Baldwin (April 25, 1775 – January 8, 1844) was a medical doctor, businessman, lawyer, judge, architect and reform politician in Upper Canada.

He, and his son Robert Baldwin, are recognized for having introduced the concept of "responsible government", the principle of cabinet rule on which Canadian democracy is based.

Faced with the prospect of the uprising of the Society of United Irishmen in 1798, he came to Upper Canada with his father and family, arriving in July 1799.

When he was not re-elected in 1831, he bitterly left politics and focused on other causes such as the response to the 1832 Cholera epidemic, the Mechanics Institute and the House of Refuge and Industry.

He and 222 inhabitants of the Home district petitioned Sheriff William Jarvis to call a public meeting to discuss Durham's recommendation on responsible government in August 1839.

When Baldwin called the meeting to order, Jarvis led an Orange Tory mob, which tore a fence apart, and began beating the defenseless crowd.

The meeting broke up, but not before a nineteen-year-old member of the Children of Peace, David Leppard, was struck in the temple with a rock with such force that he was knocked from his wagon; he was to die soon after.

The violence of the Yonge Street Durham meeting had led to strenuous objections from his wife who was "quite terrified" at the thought of his re-entering politics.

Governor pushed for the establishment of a Home District Savings Bank on June 5, 1830 "for the earnings of Journeymen Tradesmen, Mechanics, Servants, Labourers."

The day-to-day operations of the House of Industry were left to a three-member "weekly committee" composed of Baldwin, the Baptist preacher Alexander Stewart, and John Powell, an attorney.