He was born in Toronto, Ontario, the youngest son of department store magnate Timothy Eaton and his wife, Margaret Wilson Beattie.

In 1905, weeks after laying the final stone at the new store at the corner of Portage and Donald in Winnipeg,[1] John Craig (aka 'Jack') participated in several automobile races, successfully lowering the 5-mile record[2] driving a Packard.

In 1915, Eaton was made a Knight Bachelor in recognition of his participation in the war effort.

Perhaps his most lavish public contribution was the gift, made together with his mother, of land and funds for a large Methodist church on St Clair Avenue in Toronto.

These donations included Coronation Hall (1911), and the manse and organ for Trinity United Church.