San Mateo del Mar is a coastal town and municipality in Oaxaca in south-western Mexico.

San Mateo del Mar has a warm climate, with rainfall in summer and early autumn.

[5] The predominant religion in San Mateo del Mar is Christianity, including both Catholic and evangelical adherents.

[1] The first church building in San Mateo del Mar was constructed under the supervision of Spanish priests between 1591 and 1620.

[1] The health center that was built by former governor Ulises Ruiz Ortiz (PRI) in 2009 was never equipped or staffed and this neglect was cited as one of the root causes of the July 2020 dispute that led to the massacre of 15 Ikoots.

[1] In terms of agriculture, residents grow crops such as corn and vegetables, and breed cattle, pigs and goats.