The rothphone (German: Rothphon, Italian: ròthfono; also rothophone, rothaphone, or saxsarrusophone) is a metal double reed conical bore wind instrument similar to the sarrusophone, but built with a saxophone shape.

The rothphone was invented by Friedrich Roth, who initially named it the rothcorno.

Like the sarrusophone, it was intended to replace oboes and bassoons in military bands.

[1] Rothphones were patented and introduced in five sizes in 1912 by Bottali, their only significant manufacturer:[2] Each instrument corresponded in range to the similar-sized sarrusophone or saxophone, and all are transposing instruments notated in treble clef.

[2] For the same size of instrument, the bore of the rothphone is similar to the sarrusophone, and narrower than the saxophone.