Sidney Lanier High School was a public high school in Montgomery, Alabama, United States.

Established in 1910 on the southern outskirts of downtown Montgomery, Alabama, the school was named for a Southern poet, Sidney Lanier, who lived in Montgomery during 1866–67.

The high school moved to new facilities in 1929 further to the south. The late Gothic Revival building was constructed 1928–1929 to consolidate the original Lanier (then in a building now known as Baldwin Magnet School, formerly Baldwin Junior High School) and Montgomery County High School (now the Cloverdale campus of Huntingdon College, formerly Cloverdale Junior High School).

The name of the new school was decided by the outcome of a football game between the two schools in the fall of 1928, which Lanier won.

Frederick Ausfeld was the architect, and Algernon Blair the contractor. The building opened for class in September 1929 and was dubbed "The Million Dollar School" due to its approximate cost.

The school was desegregated in September 1964. The first black students graduated in the summer of 1967. As late as the 1960s, the student population of Lanier was all white. In 2004, the student population included only six white students. Besides white flight, another factor influencing this change can be found in the neighborhood schools concept adopted by the Montgomery Board of Education.

In 2020 the school district's board of education voted to change the school's name, but in 2022 the board decided to merge the school with George Washington Carver High School, and "the Lanier building will no longer be in use after the students move". The school closed in May 2024.

In 2006, Lanier was the only traditional public high school in Montgomery to meet federally mandated No Child Left Behind standards.^{[citation needed]}