Winterthur District is one of the twelve districts of the German-speaking canton of Zürich, Switzerland. It has a population of (as of ). 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.