It is 150 kilometres (93 mi) long, and is named after Sir Peregrine Maitland, Lieutenant-Governor of Upper Canada from 1818 to 1828.

The river continues west into the municipality of Howick, Huron County, where it passes over two small dams, at Gorrie (maintained by the Maitland Valley Conservation Authority) and at Wroxeter (maintained by the community),[4] passes through the municipality of Morris-Turnberry, and reaches the community of Wingham in the municipality of North Huron, where it passes over a dam and takes in the left tributary Middle Maitland River.

From the community of Auburn to Goderich, the river forms the boundary between Ashfield–Colborne–Wawanosh and the municipality of Central Huron.

The river continues southwest, takes in the left tributary South Maitland River, turns northwest, and reaches its mouth at Lake Huron at the town of Goderich.

The lower Maitland (to Wingham) has a trout and salmon run, and is home to several species at risk including queen snake, wavy-rayed lampmussel and butternut tree, as well as several Carolinian forest species, including bitternut hickory, American sycamore, summer grape and green dragon.