Toowoomba Post Office, Heritage postal building in Margaret Street, Toowoomba, Australia.

The Toowoomba Post Office is a heritage postal building located at 136 Margaret Street in Toowoomba, Australia, constructed between 1878 and 1880. Its centerpiece is a clock tower with four faces, and the walls feature a symmetrical facade made from local Highfields sandstone.

Postal service in the region started in 1845 with pack-horse mail routes running from Brisbane to Drayton, eventually leading to this building's construction. It was completed between 1878 and 1880 and served as a key postal hub for the developing town.

The building's front tower and one wing are cut from pale yellow sandstone quarried at Highfields, the same stone used for the neighbouring Court House. The clock was fitted by Mr Schoenle of Ipswich for £105. The post office is one of three surviving Classical Revival post offices in Queensland, alongside Maryborough (1866) and central Brisbane (1871); a fourth at Dalby (1867) has been demolished.

The building on Margaret Street now houses various businesses after Australia Post moved its postal operations to a different location in 1999. Visitors can view the exterior facade and clock tower closely and examine the architectural details.

In 1960 this location became the first site in Australia to install a cross-bar automatic telephone system, a breakthrough in communication technology. This technological milestone made the building significant in the nation's telecommunications history.