Sytze Wopkes Wierda (28 February 1839 in Hemrik, the Netherlands – 10 December 1911 in Sea Point, South Africa) was a Dutch architect and engineer who played an important role in the architecture of the South African Republic in the late 19th and early 20th centuries.

He was brought to the republic by State President Paul Kruger who was a great admirer of his work and wanted to establish a typically South African style of architecture with Dutch roots.

His works include numerous official buildings and structures like post offices, police stations, gaols and bridges.

Most of his buildings are located in Pretoria with the notable exception of the Rissik Street Post Office in Johannesburg.

One of his most celebrated works is the Palace of Justice on Church Square in Pretoria.