[7] At the time of the first European contact in the 17th century, the lake was called Ouentironk ("Beautiful Water") by the native Wendat/Ouendat (Huron) people.

Captain Simcoe was born on 28 November 1710, in Staindrop, in County Durham, northeast England, and served as an officer in the Royal Navy, dying of pneumonia aboard his ship, HMS Pembroke, on 15 May 1759.

(Natural Resources Canada gives a related translation: "it originated as the Mohawk phrase tkaronto, which means "where there are trees standing in the water".

[clarification needed] Mohawks used the phrase to describe The Narrows, where Hurons and other natives drove stakes into the water to create fish weirs.

Since then, many subsequent mapmakers adopted this name for it, though cartographer Vincenzo Coronelli is thought to have introduced the more commonly used spelling of Toronto in a map he created in 1695.

The watershed draining into the lake contains a population of roughly half a million people, including the northern portion of the Greater Toronto Area (GTA).

The town of Innisfil occupies the western shore south of Barrie and north of Bradford.

The narrows, known as "where trees stand in the water", an interpretation of the word 'Toronto', was an important fishing point for the First Nations peoples who lived in the area, and the Mohawk term toran-ten eventually gave its name to Toronto by way of the portage route running south from that point, the Toronto Carrying-Place Trail.

The meaning of "where trees stand in the water", is likely to have originated from Huron practice of driving stakes into the channel sediments to corral fish.

However, due to deep deposits of glacial sediments, this bedrock only appears exposed along the lakeshore on Georgina Island.

Isostatic rebound from the retreat of the last glaciers results in a steady rise of Lake Simcoe, particularly at its south end, and is further responsible for the deep organic sediments that have accumulated in its one-time shallow southern arm, known as the Holland Marsh.

Here, organic deposits created by vegetation have largely kept pace with the steady rise in water level, and today supports extensive market gardening.

Lake Simcoe has seen a dramatic decline in some fish species, along with an increase in algae blooms and aquatic weed growth.

Phosphorus emissions from both urban and rural sources have upset the lake's ecosystem and fostered excessive aquatic plant growth, raising water temperatures, and decreasing oxygen levels, thereby rendering limited breeding grounds inhospitable.

Lake Simcoe has been victim to zebra mussel, purple loosestrife, black crappie, spiny water flea, round goby, rusty crayfish and Eurasian milfoil invasions.

The Region of York is currently finalizing plans for a sewage treatment plant to be constructed on the shores of Lake Simcoe[24] to be located on the Holland River in Cook's Bay.

A number of southern Ontario rivers flow, generally north, into the lake, draining 2,581 km2 (997 sq mi) of land.

In the summer, fishing is still an attraction; however, there are also a number of poker runs, jet-skiing, and other boating events.