Marion Township is a township in Buchanan County, Missouri, United States. At the 2020 census, its population was 1159.
Marion Township was established in 1837.
Marion Township covers an area of and contains one incorporated settlement, Easton. It contains eight cemeteries: Blakely, Bowen, Courtney, Kessler, Minor, Moxley, Saint Joseph's, and Saint Mary's.
The streams of One Hundred and Two River, Becks Branch, James Branch, Third Fork Platte River, Little Third Fork, and Muddy Creek run through this township.