Changyà Ân County is a county in South Hwanghae province, North Korea.
Changyà Ân is bordered to the north by Kwail and Songhwa, to the east by Samch'à Ân and T'aet'an, to the south by Ryongyà Ân, and to the west by the Yellow Sea. Most of the land in Changyà Ân is composed of flat plains, with mountains forming its borders. The highest point is Mt. Pult'a, at .
Changyà Ân county was created under the Yi dynasty. Chaeryà Âng was briefly merged into the newly formed Hwanghae District in 1895 during an experimental redistricting, but was restored to its previous form in 1896. The county's current form was settled in the 1952 redistricting changes, when the entire south of the county was split away to form Ryongyà Ân county. In 1956 it became part of South Hwanghae Province when the former Hwanghae Province was split.
The county is served by the Changyà Ân Line of the Korean State Railway, which stops at Ragyà Ân and Changyà Ân stations. There is also a highway which runs through Changyà Ân-à Âp.
The county is divided into one town (Ã Âp), 1 Worker's District (rodongjagu) and 19 villages (ri).