The township is about 13 miles south of downtown Grand Rapids. It is directly south of the city of Kentwood. The Charter Township of Caledonia and Village of Caledonia are to the east. Leighton Township in Allegan County is to the south and Byron Township to the west.
Gaines Township was established in 1848.
In the traditional township numbering for the State of Michigan, Gaines Township is T 5 N, R 11 W.