The J. Ross Robertson Cup was donated by John Ross Robertson on December 3, 1898, to be awarded annually to the champion of the senior ice Hockey division in the Ontario Hockey Association / OHA. It was presented by and named for John Ross Robertson, the president of the Ontario Hockey Association who served from 1899 to 1905.

The trophy had been awarded to the OHA Senior A League champions from 1899 to 1987. It was not awarded from 1988 to 2001.
Allan Cup Hockey of Ontario has awarded the cup since 2002.

The cup, which is of Tazza Form was crafted by the Her Majesty's Jewellers and Silversmiths in London, England and is made of Canadian sterling silver and lined with Canadian gold. The bowl is richly decorated with a bas relief of lions, masks, fells etc. The most striking feature of this original cup is the 3 leopard handles, which are beautifully modelled and chased.

Tt's original weight was 160 ounces.
13 inches in diameter and 10 inches in height.

Each winning team receives its own shield on the plinth, with the player's names engraved on it.

The J. Ross Robertson Cup was the first of three similarly named trophies Robertson donated to the OHA, which included the J. Ross Robertson Cup for the annual champions of the junior division, and the J. Ross Robertson Cup for the annual champions of intermediate division.