Die Altstadt (German for "the old town") in the Swiss city of Zürich encompasses the area of the entire historical city before 1893, before the incorporation of what are now districts 2 to 12 into the municipality, over the period 1893 to 1934. Die Altstadt approximately corresponds to the area enclosed by the former city ramparts, and is today within the administrative area of the city called Kreis 1 (District 1).

With a population of 5,617 (as of 2015), it houses about 1.4% of the city's total population.