Ithaca is a residential locality in Red Hill, four km north-east of central Brisbane. It was formerly a municipality, the Town of Ithaca, which just before its incorporation in the greater Brisbane Council in 1925 was described as 'the salubrious suburb ... with the biggest population and the healthiest revenue' (excepting Brisbane and South Brisbane municipalities).

Ithaca was named by the colonial Governor, Sir George Bowen, who had been rector of the Ionian University at Corfu, Greece, served in the colonial government of the Ionian Islands and wrote a book titled Ithaca in 1850. His wife Diamantina Roma, was also from the Ionian Islands.

When the Ithaca local government division was formed in 1880 it extended to Enoggera and Windsor. A reconstitution of local government in 1887 severed Ithaca Shire from the division, the shire amounting to about 11.5 sq km or a tenth of the former division. The shire included Paddington and Red Hill, its population close to 10,000 persons. Ithaca Creek School opened in 1884.

In 1897 electric tram services from Roma Street to Enoggera Terrace, one along Musgrave Road and the other along Caxton Street and Given Terrace, were opened. The latter was extended towards Bardon in 1897 and the line along Musgrave Road was also extended along Waterworks Road. Two westerly lines thus flanked the suburb of Ithaca. Reticulated water was laid on by 1912 in most of the municipality.

Ithaca's elevation protected it from the ravages of the 1893 flood. The shire was designated the Town of Ithaca in 1903 and in 1910 new council chambers were opened in Enoggera Terrace, Paddington, near the Ithaca Presbyterian church (1893). The council concentrated on road and drainage works, taking the airy landscape for granted. By 1912 it found that provision for open space had been neglected, and it purchased Gilbert Park on Waterworks Road. The nearby children's play reserve (1919) was opened before a gathering of delegates to a town planning and local authorities conference. Town planning became a serious preoccupation, with the council enacting planning bylaws in 1924, assuming control over industrial areas. The following year the municipality was incorporated into greater Brisbane, at which time it was the third most densely populated metropolitan municipality, with 6.88 persons per acre (1921) (Brisbane and South Brisbane cities ranking ahead). The name endures with Ithaca Creek State School (1885), the Ithaca baths in Caxton Street, Paddington and the Ithaca branch of the Brisbane City Library in the former town hall, and the Ithaca war memorial park both in Enoggera Terrace. Several main roads have rockeries and embankments built by the town council and they, along with the town hall and the war memorial, are on the Queensland heritage register.

Ithaca Shire/Town's census populations were:

 Census DatePopulation
Ithaca Shire/Town189111,014
 190113,333
 191115,756
 192120,905
Ithaca Suburb19113378
 19478767
 19719987

Later census data is included in Red Hill.