The 1978 World Rowing Championships were World Rowing Championships that were held from 30 October to 5 November at Lake Karapiro near Cambridge, New Zealand. Twenty-eight countries were represented at the regatta. In the history of the World Rowing Championships, 1978 was the only year when the lightweight rowing championships were not held in conjunction with the open men and women event; the lightweight events had already been held in Copenhagen, Denmark, in August.

Lake Karapiro is an artificial reservoir lake on the Waikato River at Karapiro, 8 kilometres (5.0 mi) south-east of Cambridge in New Zealand's North Island. The lake was formed in 1947 by the damming of the Waikato River to store water for the 96-megawatt Karapiro power station. The lake is also one of two premier rowing venues in New Zealand and is the base for the country's high-performance rowing programme.