希芒县（Chemung County, New York）是位于美国纽约州南部的一个县，南邻宾夕法尼亚州。面积1,064平方公里。根据美国人口调查局2000年统计，共有人口91,070人。县治埃尔迈拉。

成立于1836年3月29日。县名原来是印第安部落—特拉华人的一座村落的名字。

Chemung County is a county located in the U.S. state of New York. As of the 2010 census, the population was 88,830. Its county seat is Elmira. Its name is derived from the name of a Delaware Indian village (meaning "big horn").

Chemung County comprises the Elmira, NY Metropolitan Statistical Area, which is also included in the Elmira-Corning, NY Combined Statistical Area.