Mengyin County (simplified Chinese: 蒙阴县; traditional Chinese: 蒙陰縣; pinyin: Méngyīn Xiàn) is a county in the southwest-central part of Shandong province, People's Republic of China.

It is under the administration of Linyi City.

The population was 524,565 in 1999.

[3] As 2012, this county is divided to one subdistrict, eight towns and two townships.

[4]