List of county routes in Suffolk County, New York

County routes in Suffolk County, New York are maintained by the Suffolk County Department of Public Works (SCDPW) and signed with the Manual on Uniform Traffic Control Devices-standard yellow-on-blue pentagon route marker. The designations do not follow any fixed pattern. Some route numbers are deliberately omitted in order to alleviate confusion with New York state routes (such as CR 109 and CR 114); however, this practice is inconsistent, as other numbers including 108, 111, and 112 are duplicated. These routes are officially logged inside the New York State Department of Transportation's "Local Highway Inventory", which lists all county routes for each county in the State of New York.