Arcadia Township is a civil township of Manistee County in the U.S. state of Michigan. As of the 2000 census, the township population was 621.
The unincorporated community of Arcadia is located within the township on M-22 on the shore of Lake Michigan. Arcadia is at 44°29′35″N 86°13′54″W / 44.49306°N 86.23167°W / 44.49306; -86.23167. The elevation is 587 feet (179 m) above sea level. The ZIP code is 49613.
European settlement in Arcadia dates to 1866, when Dr. W. L. Dempster, G. W. Boss, and H. Huntington settled on Bar Lake, so named because a large sandbar separates it from Lake Michigan (the lake is now called Arcadia Lake). The township was organized soon after, in 1870. The village of Arcadia was founded in 1880.