Sinclair is an unincorporated community in Butler County, Iowa, United States.

[1] Sinclair was a frequent stop for the Underground Railroad during and before the Civil War.

Prior to the establishment of the town, it was nothing more than a railroad stop.

[2] On May 25, 2008, an EF5 tornado ripped through southern Butler County, and destroyed the Sinclair grain elevator, ripping apart grain bins and throwing anhydrous ammonia tanks into fields.

This article about the geography of Butler County, Iowa is a stub.