Deagon, a residential suburb on the Sandgate railway line, is 16 km north of central Brisbane. It is partly separated from Sandgate by a series of lagoons and former water reserves, and is bounded on the south by the Cabbage Tree Creek. William Deagon was the Mayor of Sandgate town council in 1882-84. The railway line was opened in 1882 with the destination of Sandgate uppermost in mind as the beach escape for Brisbanites in the summer. Deagon was chosen by the Sandgate townspeople as the location for its local racecourse, west of the railway station. The site was reserved in 1890, and came into the hands of the Melbourne racing entrepreneur, John Wren, in 1912.
In 1908 the Blackwood housing estate around the railway station was put on the market, but most of the houses on it are post-World War I. In about 1918 an inter-denominational church was opened at the corner of Adams and Blackwood Streets, east of the station. Residents were scattered along Board Street at addresses closer to the station, and there was a store near the church. The post office directory (1949) recorded a steady growth in population: shopping included a cash and carry grocer and three mixed businesses, and there were two nursery owners and a motor garage. The racecourse became a training track in 1941, so numerous trainers lived in Deagon along with a blacksmith.
Sandgate High school was built in Deagon in 1959. Additional local shops were opened in 1990 next to the high school, providing a supermarket and 13 shops at the drive-in Deagon Plaza.
Sandgate's main venue for sports is the Deagon sportsground, next to the horse-training track. Deagon's census populations have been: