Macdona is an unincorporated community and census-designated place in Bexar County, Texas, United States. As of the 2020 census, Macdona had a population of 464. Macdona lies along the Union Pacific rail line near Loop 1604 in southwest Bexar County. It is part of the San Antonio Metropolitan Statistical Area.
Macdona was named for George Macdona, an Englishman, who owned the townsite. The first recorded sale of town lots was dated July 7, 1886. The Macdona post office (78054) opened in 1886. On September 1, 1909, the Artesian Belt opened a line between Macdona and Christine. In 2000, Macdona was reported to have 297 persons. The town is part of the 210 and 726 area code districts.
Macdona first appeared as a census designated place in the 2010 U.S. census.
The climate in this area is characterized by hot, humid summers and generally mild to cool winters. According to the Köppen Climate Classification system, Macdona has a humid subtropical climate, abbreviated "Cfa" on climate maps.
On June 28, 2004, a crash between BNSF and Union Pacific Railroad trains in Macdona resulted in the release of of liquid chlorine, which immediately vaporized into a cloud of chlorine gas that spread over a radius of at least . Three people, the UP train conductor and two residents, died, and at least 40 others were injured.