Muak Lek is a district (amphoe) located in the easternmost part of Saraburi province, Thailand. It is situated within the Dong Phaya Yen Mountains, which serve as a geographical divide between the central and northeastern regions of the country.
Originally characterized by dense jungle, much of the area's forest cover was cleared during the 20th century. However, several forested hills remain, featuring natural landmarks that serve as tourist destinations. These include portions of Namtok Chet Sao Noi National Park and Khao Yai National Park located within the district boundaries.
The region is also notable for its agricultural contributions, specifically dairy farming. This industry was first introduced to Thailand in 1962 and remains an important economic activity for the Muak Lek district today.