Armstrong is an American flute maker founded in 1931 by William Teasdale Armstrong, a former C.G. Conn shop foreman who opened a small flute repair shop in Elkhart, Indiana. The business grew from repairs into manufacturing, eventually passing to his son Edward and becoming one of the most widely played student flute brands in North America. In 1984 the company was acquired by King Musical Instruments, later folding into United Musical Instruments and then into Conn-Selmer, which produces the brand today.

The line is focused almost entirely on flutes aimed at students, school bands, and step-up players, with a smaller range of intermediate and alto models. The Armstrong 104 is the brand's best-known student flute — a silver-plated, closed-hole instrument with an offset G and the brand's CNC-cut key cups — and is a standard rental and beginner horn in many U.S. school programs. The 303 series covers open-hole sterling-silver headjoint models for advancing students, and the AFC301 concert flute and Armstrong alto flute sit at the top of the current catalog.

In the 1970s, Armstrong worked with British flute maker Albert Cooper on a revised scale with a tapered headjoint and reworked tone-hole placement, elements of which carried forward into later Armstrong designs. The brand's reputation sits firmly on the student and educational side of the flute market rather than on the professional concert or jazz circuit.

Armstrong has 11 products cataloged on Equipboard, including Flutes. Their gear is featured by 6 artists, with the strongest followings in Rock, Pop, and Folk, World, & Country. Notable users include Stu Mackenzie, Rodrigo Amarante, and Thijs van Leer.