Matuguinao, officially the Municipality of Matuguinao (; ), is a municipality in the province of Samar, Philippines. According to the 2024 census, it has a population of 7,708 people, making it the least populated municipality in the province.
Matuguinao or Matugnaw is a Waray-Waray word that literally means cold.
Matuguinao was named as a municipal district of Gandara in the year 1948 to 1960. By virtue of Republic Act No. 4221, which divided the old province of Samar, it was later converted into a municipality and a part of the newly established province of Western Samar (now Samar) in 1965.
Matuguinao is politically subdivided into 20 barangays. Each barangay consists of puroks and some have sitios.