David Edward Crombie PC OC OOnt (born April 24, 1936) is a former Canadian academic and politician who served as the 56th mayor of Toronto from 1972 to 1978.

Crombie was the first mayor who represented the reform movement of Toronto politics, and his policies differed sharply from those of the Old Guard who preceded him.

Crombie then put forward a new official plan that imposed varying height restrictions across the city, and this was upheld by the board.

He was more successful in countering plans for the Scarborough Expressway; all work was halted during Crombie's term, leading to its eventual cancellation.

Instead, he oversaw the creation of the St. Lawrence neighbourhood, an area of mid-rise, mixed-use, mixed-income buildings that followed Jane Jacobs's vision of urban planning.

Because of his great public appeal and his height of only 5 feet 5 inches (1.65 m),[6] he was repeatedly described in the media as the city's "tiny, perfect mayor".

He left City Hall in 1978 to move to federal politics, winning a by-election as a Progressive Conservative candidate that gave him a seat in the House of Commons of Canada.

Frustrated in Ottawa, as a Red Tory in an increasingly conservative government, Crombie decided not to run in the 1988 election and returned to urban affairs as head of the royal commission on the Future of Toronto's waterfront (1988–92).

In 1999, Crombie founded the Waterfront Regeneration Trust, as a charity, to continue the work of the provincial agency, and serves on the Board.

Crombie tried to find an alternative to Red Hill Creek Expressway but the Hamilton city council dismissed his compromise proposal out of hand as being insufficient.

Throughout the 1990s, he served in various advisory capacities to city and provincial governments relating to urban issues in the Toronto area.