锡马龙县（英语：Cimarron County, Oklahoma）是美国奥克拉荷马州最西部的一个县，北邻科罗拉多州，东北邻堪萨斯州，西邻新墨西哥州，南邻德克萨斯州。面积4,769平方公里。根据美国2000年人口普查，共有人口3,148人，是全州人口最少的县。县治博伊西市。

纵观锡马龙县的历史，锡马龙县一直都是奥克拉荷马州中人口最少的县份。根据2010年人口普查，锡马龙县共有人口2,475人。成立于1889年，并且于1907年独立自比佛县。县名来自锡马龙河（西班牙语「野羊河」的意思）。该州的最高点布莱克峰位于本县。

Cimarron County is the westernmost county in the U.S. state of Oklahoma. As of the 2010 census, the population was 2,475, making it the least populous county in Oklahoma. Its county seat is Boise City.

Located in the Oklahoma Panhandle, Cimarron County contains the only community in the state (Kenton) that observes the Mountain Time Zone. Black Rock Mesa, the highest point in the state, is in the northwest corner of the county. Throughout most of its history it has had the smallest population and the lowest population density of any county in Oklahoma.