Zhaoyuan County (Chinese: 肇源县; pinyin: Zhàoyuán Xiàn), formerly Rear Gorlos Banner, is a county in the west-central part of Heilongjiang Province, China, bordering Jilin province to the south. The southernmost county-level division of Daqing City, it has a land area of 4,198 km² (1,621 sq mi) and a population of 450,000. The postal code is 166500. The county seat is located in Zhaoyuan Town.

Some farms in Zhaoyuan county with alkaline soil are experimenting rice cultivation with hybrid saltwater-tolerant rice.

Zhaoyuan consists of 8 towns and 8 townships.

45°31′26.36″N 124°42′05.36″E / 45.5239889°N 124.7014889°E / 45.5239889; 124.7014889