The Today Network started when the Austereo Radio Network secured the first commercial FM licence in Adelaide in 1980. Austereo launched a station called Double SA FM, which has since changed to SAFM. Austereo bought Fox FM Melbourne in 1986, bought and converted 4BK in Brisbane to B105 in 1988 and bought 2Day FM in Sydney in 1989. The network also grew through joint-ventures in Canberra with 104.7 and NXFM Newcastle (now fully owned). Austereo expanded into Perth in 1998 when it purchased PMFM (now 92.9), although it wasn't until 2005 that the station exclusively joined the Today Network, after also being affiliated with sister station Triple M for many years and taking programming from both networks.
The network was previously known as "Today's Austereo Network", however the name was recently shortened to the current title.
After Austereo was purchased by Southern Cross Media, it began incorporating its regional CHR network into the Today Network. Currently, only some of its Sea FM stations, including those in Hobart and the Gold Coast, use similar branding to the other metropolitan stations.
The Today Network launched Caravan Radio on 24 May 2010. It is a "pop up" Digital Radio station that plays the best bits from Hamish & Andy's Caravan of Courage journeys while they toured the United Kingdom on their fourth Caravan of Courage.