Pengyang County (simplified Chinese: 彭阳县; traditional Chinese: 彭陽縣; pinyin: Péngyáng Xiàn, Xiao'erjing:پٍْ‌يَانْ ثِيًا) is a county under the administration of the prefecture-level city of Guyuan in Ningxia Hui Autonomous Region of China, bordering Gansu province to the due north, east, and south.

It has a total area of 3,241 km2 (1,251 sq mi), and a population of approximately 250,000 people.

Its primary agricultural product is wheat, but in recent years the county has also developed forestry.

In this it is a model county for Ningxia Hui Autonomous Region.

Because of the bad weather and inconvenient location, it always gets financial aid from government.