What type of fly do classic Levi's 501 jeans have?

Classic Levi’s 501 jeans have a button fly.

The button fly is one of the defining features of the 501 Original, distinguishing it from many other jeans that use a zipper. A row of metal buttons closes the front opening rather than a slide fastener, giving the garment its instantly recognizable traditional construction.

The design dates back to the workwear origins of Levi Strauss & Co.’s riveted trousers. In the 19th century, denim waist overalls were made for miners, laborers, and other customers who wanted durable clothing. The 501 name was introduced as a lot number in 1890, while the jeans retained details such as a straight-leg cut and button closure.

A common mix-up is assuming every Levi’s model has a button fly. Many later styles, including the 505, use a zipper fly. Modern 501 variations can differ in fabric, wash, and fit, but the button fly remains the classic model’s signature detail.