Winterthur District is one of the twelve districts of the German-speaking canton of Zürich, Switzerland. It has a population of 173,053 (as of 31 December 2020). Its capital is the city of Winterthur.

Winterthur District contains a total of 19 municipalities:

On 1 January 2014 the former municipality of Bertschikon merged into the municipality of Wiesendangen.

On 1 January 2018 the former municipality of Hofstetten merged into the municipality of Elgg.