Gregory is an unincorporated community in Livingston County in the U.S. state of Michigan. The community is located within Unadilla Township. As an unincorporated community, Gregory has no legally defined boundaries or population statistics of its own but does have its own post office with the 48137 ZIP Code.

Livingston County is a county in the U.S. state of Michigan. As of the 2020 Census, the population was 193,866. It is part of the Detroit-Warren-Dearborn, MI Metropolitan Statistical Area. The county seat and most populous city is Howell. The county was platted in 1833, but for three years remained assigned to Shiawassee and Washtenaw counties for revenue, taxation and judicial matters. It was formally organized in 1836. As one of Michigan's "Cabinet counties", a group of ten counties whose names honor members of President Andrew Jackson's Cabinet, it is named after former US Secretary of State Edward Livingston. Livingston County's location in Southeast Michigan offers residents relatively convenient access to the metropolitan centers of Detroit, Lansing, Ann Arbor, and Flint. Livingston County residents regularly commute to those centers, using the three major expressways which pass through the county: I-96, US 23, and M-59. Although continuing to be composed largely of bedroom communities, the county is experiencing and maintaining significant growth in both the service and industrial economic sectors. Major employers include Tribar, PepsiCo, Citizens Insurance, and ThaiSummit. The Brighton Recreation Area is in the county.