Samut Sakhon Province, originally known as "Ban Tha Chin," was established as a significant settlement during the Ayutthaya period, where it served as a port and marketplace for Chinese merchant ships. In 1556, during the reign of King Maha Chakkraphat, Ban Tha Chin was elevated to "Sakhon Buri," becoming a strategic military and trade outpost for defense against invasions by sea. Later, in the Rattanakosin era, King Mongkut (Rama IV) renamed the area "Samut Sakhon," meaning "City of Sea and River." In 1913, under King Vajiravudh (Rama VI), "Samut Sakhon" was officially designated as a province.

The name "Mahachai," often associated with Samut Sakhon, originates from the Mahachai Canal, an important waterway completed under King Thai Sa's rule. This canal allowed a more direct route from Thonburi to the mouth of Sakhon Buri, fostering community growth along its banks. During King Chulalongkorn’s reign (Rama V), Samut Sakhon saw further administrative advances, including the establishment of the "Tha Chalom Sanitary District" in 1905—the first of its kind in Thailand, marking a significant milestone in regional governance and public infrastructure.