Mackay Customs House is a heritage-listed customs house at 31 River Street, Mackay, Mackay Region, Queensland, Australia. The design is attributed to John Smith Murdoch and the builder was MS Caskie. It was completed in April 1902. It was added to the Queensland Heritage Register on 7 February 2005.

Mackay is a city in the Mackay Region on the eastern or Coral Sea coast of Queensland, Australia. It is located about 970 kilometres (603 mi) north of Brisbane, on the Pioneer River. Mackay is described as being in either Central Queensland or North Queensland, as these regions are not precisely defined. More generally, the area is known as the Mackay–Whitsunday Region. Nicknames of Mackay include the Sugar capital, Alexandra and Macktown. The demonym of Mackay residents is Mackayites.