From 1923 to 1928 the Brisbane City Council implemented its most ambitious town improvement scheme to that date: the widening of Adelaide Street by 14 feet (4.3 m) along its entire length.

The work was undertaken in stages, commencing in 1923 at the southern end where the new Brisbane City Hall was under construction.

[5] A number of locations on Adelaide Street are listed on the Queensland Heritage Register, including: The Atlas Café, located at Atlas Chambers, 27 Adelaide Street in Brisbane’s CBD, was operated by Greek migrant George Sklavos, starting some time during the mid-1920s.

Sklavos is first listed as the proprietor of the Atlas Cafe in the 1927–1928 edition of the Queensland Post Office Directory.

ANZAC Day parades, in which Australian war veterans (and war veterans of allied nations) march, take place in Adelaide Street, on 25 April every year, and Dawn services are held at the Shrine of Remembrance within ANZAC Square at Adelaide Street.