加勒特县（Garrett County, Maryland）是美国马里兰州最西部的一个县，东 (部分)、南、西邻西维吉尼亚州，北邻宾夕法尼亚州。面积1,699平方公里。根据美国2000年人口普查，共有人口29,846人。县治奥克兰 (Oakland)。

成立于1872年，是该州最近成立的县。县名纪念巴尔的摩与俄亥俄铁路的主席约翰·沃克·加勒特 (John W. Garrett)。约克加尼河 (Youghiogheny River)是该州唯一属密西西比河流域的河流。

Garrett County (gərɛt) is the westernmost county of the U.S. state of Maryland. As of the 2010 census, the population was 30,097, making it the third-least populous county in Maryland. Its county seat is Oakland. The county was named for John Work Garrett (1820–1884), president of the Baltimore and Ohio Railroad. Created from Allegany County, Maryland in 1872, it was the last Maryland county to be formed.