William Deagon was an old identity of the area, and his name was used for the locality when the railway line went through in 1887. He owned the Sandgate Hotel, a stopping place for the Cobb & Co. coaches. Deagon Street, the racecourse, the railway station and the Deagon Wetlands now bear his name.

Deagon Post Office opened on 18 June 1947 at Mr Torpie's store next to the railway station.

In the 2011 census, Deagon recorded a population of 3,460 people, 51.8% female and 48.2% male.

The median age of the Deagon population was 40 years of age, 3 years above the Australian median.

77.5% of people living in Deagon were born in Australia, compared to the national average of 69.8%; the next most common countries of birth were England 5%, New Zealand 4.3%, Philippines 0.9%, Scotland 0.6%, South Africa 0.5%.

90.4% of people spoke only English at home; the next most popular languages were 0.4% German, 0.3% Polish, 0.3% Tagalog, 0.3% Hindi, 0.3% Japanese.

A Queensland Racing training facility, Deagon Racecourse, lies to the north of the suburb. Horse racing in Deagon ceased in 1941, but the racecourse remains a first rate training establishment. The Bligh government intended to make the racecourse the centre for all greyhound racing in Brisbane (replacing Albion Park Raceway) but this plan was cancelled in February 2012.

The Gateway Arterial Road runs through the western side of the suburb.

The (Evergreen) Ching Chung Taoist Temple sits next to the Gateway Arterial Road. It was built at Deagon in 1991. There are three Halls which were built according to Taoist beliefs. The three halls are: The Hall of Three Purities, the Hall of Three Masters and the Hall of the Spiritual Garden. There is also a Memorial Hall of Ancestors.

Deagon has a flat topography with one of its boundaries being Cabbage Tree Creek. The Creek's catchment is largely urbanised but the Boondall Wetlands, which is separated from Deagon by the Creek, plays an important role in providing essential habitat for a range of birds and animals, including migratory birds, which make their way from the arctic circle. The Boondall Wetlands near Deagon have ecosystems that are fresh as well as areas that are salt water. The smaller reserves such as Brighton and Deagon Wetlands are fresh water only. The Deagon Wetland is an important remnant of tea tree woodland on a 50ha site. Notable bird species include the striped honeyeater and the white-cheeked honeyeater.

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Wikipedia