The trumpet is the musical instrument with the highest register in the brass family. Trumpets are among the oldest musical instruments, dating back to at least 1500 BC. They are played by blowing air through closed lips, producing a "buzzing" sound that starts a standing wave vibration in the air column inside the instrument. Since the late 15th century they have primarily been constructed of brass tubing, usually bent twice into a rounded oblong shape.

There are several types of trumpet; the most common is a transposing instrument pitched in B♭ with a tubing length of about 148 cm. Earlier trumpets did not have valves, but modern instruments generally have either three piston valves or, more rarely, three rotary valves. Each valve increases the length of tubing when engaged, thereby lowering the pitch.

A musician who plays the trumpet is called a trumpet player or trumpeter.

The earliest trumpets date back to 1500 BC and earlier. The bronze and silver trumpets from Tutankhamun's grave in Egypt, bronze lurs from Scandinavia, and metal trumpets from China date back to this period. Trumpets from the Oxus civilization (3rd millennium BC) of Central Asia have decorated swellings in the middle, yet are made out of one sheet of metal, which is considered a technical wonder. The Moche people of ancient Peru depicted trumpets in their art going back to 300 AD. The earliest trumpets were signaling instruments used for military or religious purposes, rather than music in the modern sense; and the modern bugle continues this signaling tradition.