Welland County (area, excluding cities was 226,970 acres) is a historic county in the Canadian province of Ontario.
The county was formed in 1845 from Lincoln County. The county was named from the Welland River. The river got its name from John Graves Simcoe who named it after the River Welland which forms a border of Lincolnshire, England. Niagara Falls, and the Townships in this county were among the earliest settlements in Upper Canada.
In some census and election records from the late 19th century, the townships of Pelham and Wainfleet (which can be seen on the map below) were enumerated as part of Monck County. However, Monck never existed as a county in the political sense, but only as an electoral district.
In 1970, Lincoln and Welland Counties were amalgamated to form the Regional Municipality of Niagara.