The 20th century marked a period of growth and transformation for South Brisbane, particularly in education and community infrastructure. In 1919, the Brisbane High School for Girls, now known as Somerville House, moved to its current location at Cumbooqueepa on Vulture Street. Originally founded by Eliza Fewings in 1899 in the basement of the Baptist City Tabernacle, the school later relocated to Erneton on Wickham Terrace in 1912. In 1918, it was acquired by the Presbyterian and Methodist Schools Association. The South Brisbane Town Hall, which became part of the school premises on 15 June 1999, now serves as an integral part of the campus.

Education continued to flourish in the area with the opening of St Laurence’s College for boys on 11 July 1915. Operated by the Christian Brothers, the Catholic school was officially inaugurated and blessed by Archbishop James Duhig.

Honoring those who served in World War I, the South Brisbane Memorial Park was established in 1921. The South Brisbane City Council designated a triangular piece of land at the intersection of Stanley Street, Vulture Street, and Sidon Street for the park, directly opposite the South Brisbane Town Hall. The memorial was formally dedicated on 6 August 1923 by Australia’s Governor-General, Henry Forster.

In 1925, Brisbane State High School relocated to its current Vulture Street location. The site had been considered for a public grammar school since 1867. The institution was initially formed on 1 July 1921 through the merger of the High School Department of Brisbane Central Technical College and Brisbane Junior State High School. It originally operated from the Brisbane Normal School building on the corner of Adelaide and Edward Streets before moving to South Brisbane in 1925.

Religious institutions also played a key role in shaping the community. On 10 May 1931, a second St Thomas' Anglican Church was built at 68 Grey Street, near Fish Lane. Constructed with white stucco, the church was overseen by St Andrew’s Anglican Church and served as a mission church for the largely industrial and waterfront area. The exact date of its closure remains uncertain, but it was likely before the establishment of the third St Thomas’ Anglican Church in 1962. The original church building no longer exists.

These developments reflect South Brisbane’s evolution throughout the 20th century, with a strong focus on education, community remembrance, and religious outreach.