Marvin I. Greenwood (January 31, 1840 – December 27, 1917) was an American lawyer and politician from Wayne County, New York.
He left the family farm to read law in the office of L. M. Norton in Newark, and in 1868 he was admitted to the bar.
A steadfast Republican, he served as justice of the peace for several terms and was District Attorney of Wayne County from 1877 to 1879.
[1] In 1897, Greenwood was elected to the New York State Assembly as a Republican, representing Wayne County.
He was also a charter member of the First Baptist Church of Newark as well as its Senior Deacon, clerk, and Sunday School teacher.