Luodian County (simplified Chinese: 罗甸县; traditional Chinese: 羅甸縣; pinyin: Luódiàn Xiàn) (Bouyei language: Lachos xianq) is a county under the administration of Qiannan Buyei and Miao Autonomous Prefecture in the south of Guizhou province, China, bordering Guangxi to the south.

The climate in the area is humid subtropical, with strong monsoon influences bringing heavy rain during the summer. Winters are dry due to the influence of the Siberian high-pressure system.

The county seat and the largest town in the county is also named Luodian; it was formerly known as Longping.

The county is frequented by both Chinese and foreign geologists, with the core area of work called Big Guizhoutan, or Big Guizhou Shoal. This has been called a "treasure land for Triassic Period research."

Luodian County is divided into 1 subdistrict, 8 towns and 1 township:

In 629, the Tang dynasty put Le'an County (now Luodian) under the jurisdiction of Zhuangzhou.

Luodian was the seat of the Yi-speaking Luodian Kingdom (羅甸國) in the 9th century.

In 1292, Yuan dynasty set up Yuanfu, Le'an County was renamed Luobo County, and was put under its jurisdiction.