Jan Zachwatowicz (4 March 1900 – 18 August 1983) was a Polish architect, architectural historian, and restorer.

He was a professor of the Warsaw University of Technology (since 1946; he worked there since 1925), member of the Polish Academy of Sciences (since 1952), member of the Académie d'architecture in Paris (since 1967), member of the International Council on Monuments and Sites, general restorer of relics in Poland (from 1945 to 1957; Polish: Generalny Konserwator Zabytków), chairman of the Architectural-Restoration Committee (since 1971; Polish: Komisja Architektoniczno-Konserwatorska), and chairman of the Civil Committee of Royal Castle in Warsaw Reconstruction (Polish: Obywatelski Komitet Odbudowy Zamku Królewskiego w Warszawie).

Zachwatowicz contributed to reorganization and enlargement of the Polish restoration service.

During the occupation of Poland (1939–1945) he took part in teaching, protecting and saving works, i.e. set of relic buildings measurements (including The Market Square of Warsaw Old Town).

After World War II, many other historic buildings in Gdańsk, Poznań, and Wrocław were restored or rebuilt according to principles established by Zachwatowicz and his team.