科布县（英语：Cobb County）是位于美国佐治亚州的一个县，成立于1832年12月3日。根据2000年人口普查，科布县的人口有607,751人，且不断增长。2006年，美国人口调查局估计人口为679,325人。县政府所在地位于县中心的玛丽埃塔。

科布县以法官托马斯·威利斯·科布（Thomas W. Cobb）命名。他19世纪初期担任格鲁吉亚州众议员和参议员。他也在格鲁吉亚州高等法院任法官。

科布县位于亚特兰大都会区的核心部分。地方统计上，亚特兰大都会区纳入亚特兰大-山地泉-玛丽埃塔都会统计区（Metropolitan Statistical Area）。

Cobb County is a suburban county located in the U.S. state of Georgia. As of the 2015, the population was 741,334, making it the fourth-most populous county in Georgia. Its county seat and largest city is Marietta.

Cobb, along with several adjoining counties, was created on December 3, 1832, by the Georgia General Assembly from the huge Cherokee "county" territory—land northwest of the Chattahoochee River which the state confiscated from the Cherokee Nation and redistributed to settlers via lottery, following the passage of the federal Indian Removal Act. The county was named for Thomas Willis Cobb, a United States representative and senator from Georgia. It is believed that Marietta was named for his wife, Mary.