Josef Franz Wagner (20 March 1856 – 5 June 1908) was an Austrian military bandmaster and composer. He is sometimes referred to as "The Austrian March King".

He is best known for his 1893 march "Unter dem Doppeladler" (Op. 159) or "Under the Double Eagle", referring to the double eagle in the coat of arms of Austria-Hungary. The march became a favourite part of the repertoire of American composer and bandleader John Philip Sousa, whose band recorded it three times. The piece was the official regimental march of Austrian Artillery Regiment Number 2 until its dissolution in 2007.

The tune was parodied in the Benny Goodman recording "Benjie's Bubble" and was also used for the well-known Monty Python's Flying Circus animation segment "Conrad Poohs And His Dancing Teeth".

"Under the Double Eagle" is well known in country music, having been recorded by a number of guitar and banjo players, several of them identified with the bluegrass style.

Wagner is also known for the march "Tiroler Holzhackerbuab'n" (Op. 356), or "Tyrolean Lumberjacks". In 1895, his only opera, Der Herzbub, premiered in Vienna.