Oconto is home to Copper Culture State Park, which has remains dated to around 5000-6000 B.C.

The French Jesuit, Roman Catholic priest, and missionary, Father Claude-Jean Allouez said the first Mass in Oconto on December 3, 1669.

[4] The Menominee living here began participating in the fur trade network and converting to Christianity.

[3] This area was included in the land ceded by the Menominee to the United States government in the 1836 Treaty of the Cedars.

In this treaty, the Menominee ceded over four million acres of land after years of negotiations about how to accommodate the Oneida, Stockbridge-Munsee, and Brothertown peoples who were being removed from New York to Wisconsin.

[5] Following the treaty, the land became officially available for American settlement, although soldiers and lumberers had already been here for some time.

[7] The name Okāqtow is a Menominee name meaning "the place of the pike", one of several pike-related place-names in the area.

[17] In the summer of 1952, during a two-day period, an estimated 175,000,000 leopard frogs emerged from nearby marshes and enveloped the town.

The water level of Lake Michigan rose in the spring, flooding the wetlands.

However, in 1952, Lake Michigan remained high, and a huge number of frog eggs grew into live amphibians.

The table with historical census data[24] indicates that the population has remained relatively flat throughout the 20th century.

The following schools are located in Oconto:[27] J. Douglas Bake Memorial Airport (KOCQ) serves the city and surrounding communities.