EllisDon is an employee-owned construction services company that was founded and incorporated in 1951 in London, Ontario, Canada, by brothers Don and David Ellis Smith.

Between 1956 and 1968, EllisDon computerized its accounting and cost control systems, and operated a purchased tower crane – the first construction company in Canada to do both.

[11] In 2004, EllisDon participated in a new hospital funding model, a public-private partnership (PPP) with the $450 million William Osler Health Centre in Brampton, Ontario.

[14] In June 2016, EllisDon launched The Carbon Impact Initiative Action Plan[15] in support of Canada's international climate change commitments.

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