Portland High School is located in Portland, Tennessee, United States. It is part of Sumner County Schools. PHS offers courses including two foreign languages, sciences, social studies, math, English, welding, agricultural studies, family and consumer sciences, cosmetology, art, and band.

PHS has a school population of approximately 1200 students in grades 9–12.

Serving as the flagship for Sumner County education, Portland High School was the first four-year public high school in the county. The school began in 1874 as Portland Seminary and sat on a 1-acre (4,000 m²) plot of land donated by J.C. Buntin, the son of the town's founder. The building had two stories, the second being used by the Grange. The first story was also used for church services. In 1897 the principal of the school, Professor Z.K. Griffin, was conducting a lab experiment when a fire broke out destroying the building.

A new building was completed in 1898 and was called Portland Seminary. The building was used until abandoned in 1915. From 1910 until 1915, the school was called Portland High School, but it only provided three years of secondary education. Pat W. Kerr was principal from 1910 to 1913. In 1913, P.L. Lloyd became principal and served until 1914, when John W. Williams assumed the position. Almost immediately, the student body outgrew the building. A new school was built in 1915 and was christened Sumner County High School, the first four-year public high school in the county. It had no library, no labs, and only one teacher with a college degree.

B. F. Smith followed Mr. Williams as principal; he served from 1927 until 1931. During this period, the Sumner County Board of education promised a new school building for the increasing student body, a promise fulfilled during the 1931–32 school year. Mr. Smith was succeeded by C.F. Allen, who served from 1931–1935.

Serving as principals for the next several years were Harry Law (1935–1937), Lee Harris (1937–1939), and C.L. Cummings (1939–1942). In 1940, under the leadership of Mr. Cummings, Sumner County High School became the first accredited high school in the county, receiving this honor from the Southern Association of Secondary Schools.

Following Mr. Cummings were principals C.O. Jett (1943–1945), E.V. Walling (1945–47), William Hunter, and Clarence Terry. By 1956, the school's teaching staff had undergone a major change, with almost 100% of the teachers holding college degrees. In the fall of 1960, an alumnus, William Coker, became principal and served until the beginning of the school year in 1974. In 1971, Mr. Carl Fussell became the first part-time vice principal. This position became full-time in 1973 with the hire of Mr. John Meece, who served as vice principal until 1984 when he assumed the principalship

The year 1961 saw the last graduating class from Sumner County High School. In January 1962, the school moved into a new building on South Broadway, and the name returned to Portland High School, as other areas of the county were now offering public secondary education. The old school building became Portland Junior High. The building burned in 1967, leaving only the gym, which is now called Richland Gym. Following the fire, the junior high and high school classes met in the same building using split sessions until a new junior high/middle school could be built.