En saga, Op. 9, is a single-movement tone poem for orchestra written from 1891 to 1892 by the Finnish composer Jean Sibelius. The piece, which likely began as a septet or octet for flute, clarinet, and string ensemble before evolving into an orchestral tone poem, premiered on 16 February 1893 in Helsinki with Sibelius conducting the Helsinki Orchestral Association. A decade later in 1902, Sibelius substantially revised En saga in response to an invitation from Ferruccio Busoni to conduct the piece in Berlin. It thus stands alongside The Lemminkäinen Suite (Op. 22), the Violin Concerto (Op. 47), The Oceanides (Op. 73), and the Fifth Symphony (Op. 82) as one of the most overhauled works in his œuvre. The Berlin concert, which occurred a fortnight after Robert Kajanus had premiered the revised version in Helsinki on 2 November, finally brought Sibelius the German breakthrough he had long desired.

Paavo Allan Engelbert Berglund was a Finnish conductor and violinist.