The bull had a diamond shaped white patch on its head and found difficulty crossing the creek.

Thus the Bullocky named the town after the bull with the diamond shape on its head and the creek it drowned in.

[7] In the postwar years, population increased dramatically in Diamond Creek and its neighbouring areas.

Diamond Creek remained relatively untouched during the boom in recreational travel that followed the popularity of the motor car.

[7] The St John's Anglican church complex in Main Street includes a Sunday school and parish hall.

[11] The Diamond Creek Community Centre is jointly administered by the Shire of Nillumbik and the YMCA, and provides a venue for basketball, gymnasium and group fitness classes, child care, community classes and public and private functions.

The Community Centre served as an evacuation point, providing emergency accommodation, first aid and government relief to local residents affected by the February 2009 Victorian bushfires.

The fair offers food, crafts and fairground attractions, rides, wood chopping, local community stallholders, and entertainment.

It traditionally concludes with an evening torchlight parade by the local CFA units and a fireworks display.

The Diamond Creek CFA brigade has approximately 60 members, one pumper, two tankers, a slip on ute and a Toyota Hilux FCV, as well as an extensive collection of modern, advanced firefighting equipment and training facilities.

In February 2013, the shop re-opened after a benefactor donated funds for the hospital to meet the cost of the renovations.

They meet at the Diamond Creek Netball Club[14] A new dedicated ambulance home base was opened in April 2019.

Araluen, a disability support service in Diamond Creek, run the cafe three days a week.