The Hoddle Grid is the contemporary name given to the approximately 1-by-0.5-mile grid of streets that form the Melbourne central business district, Australia. Bounded by Flinders Street, Spring Street, La Trobe Street, and Spencer Street, it lies at an angle to the rest of the Melbourne suburban grid, and so is easily recognisable. It is named after the surveyor Robert Hoddle, who marked it out in 1837, establishing the first formal town plan. This grid of streets, laid out when there were only a few hundred settlers, became the nucleus for what is now Melbourne, a city of over five million people.

The Melbourne central business district is the city centre and main urban area of the city of Melbourne, Victoria, Australia, centred on the Hoddle Grid, the oldest part of the city laid out in 1837, and includes its fringes. The Melbourne CBD is located mostly in the local government area of the City of Melbourne, which also includes some of inner suburbs adjoining the CBD, while a small section extends into the City of Port Phillip.