The town's name originated from the indigenous term "gulum" or "kulum," meaning "blunt" or "headless," in reference to Mount Coolum's shape.
The Coolum district encompasses the traditional land of the 'Inabara' or 'Yinneburra' clan from the Undanbi tribe, which was a subset of the larger group known as Kabi Kabi (or Gubbi Gubbi).
In 1823, the first Europeans passed through Coolum as castaways, who were later followed by shipwrecked sailors.
The name Coolum was first recorded in 1842. The Bunya Proclamation prohibited the granting of grazing leases in the area where Bunya trees grew.
In 1871, Grainger Ward made the first selection of land with a pastoral lease of 255 hectares, where he ran upwards to 300 head of cattle.
Coolum Provisional School opened on 2 April 1917. In 1930, it became Coolum State School.
In December 1923, land in the Mt Coolum Beach Estate second section went to auction, following the successful sale of portions in the first section, and one month after the official opening of the Moreton Central Sugar Mill Cane Tramway extension to Coolum. All lots were described as having an uninterrupted view of the Pacific Ocean.
In 1931, the Coolum Beach branch of the Queensland Country Women's Association were donated a block of land and purchased the adjacent block at 7-9 Coolum Terrace (26°31′57″S153°05′30″E / 26.5326°S 153.0917°E / -26.5326; 153.0917 (CWA Hall (former))). In 1965, a former school building was moved onto the block which was replaced with a new building in 1990. In 2013, the CWA decided that the hall was under-utilised and that its increasing property value should be realised to support other projects. The property was sold into private ownership on 21 September 2013 for $660,000.
Holy Spirit Anglican Church was dedicated on 14 November 1970. It was consecrated by ArchbishopFelix Arnott on 5 November 1977.
Coolum State High School opened on 29 January 1985.
The Coolum Library opened in 1989 with a major refurbishment in 1997.
Coolum State High School is a government secondary school for boys and girls at Havana Road East (26°30′07″S153°05′10″E / 26.5019°S 153.0862°E / -26.5019; 153.0862 (Coolum State High School)); the school services grades 7 through 12. In 2018, the school had an enrolment of 1,092 students with 88 teachers (84 full-time equivalent) and 34 non-teaching staff (26 full-time equivalent). It includes a special education program.
Despite the name, Coolum Beach Christian College is in neighbouring Yandina Creek.
Coolum Beach is a popular day trip and holiday destination. The town is focused around the beach, which is patrolled by life savers and offers swimming and surfing; in its day, the beach is known as one of the best breaks in Queensland. Parks, a boardwalk, esplanade shops, and the surf lifesaver club surround the beach. Over the last five years Coolum Beach has seen heavy development, with new buildings for retail business and holiday apartments.