Tiriel, Op. 41, is a 1985 opera by the Russian composer Dmitri Smirnov in three acts with a symphonic prologue to his own English libretto after a poem of the same title by William Blake. It has been translated into Russian and German. It was first performed at the Stadttheater Freiburg on 28 January 1989.

Dmitri Nikolaevich Smirnov was a Russian-British composer and academic teacher, who also published as Dmitri N. Smirnov and D. Smirnov-Sadovsky. He wrote operas, symphonies, string quartets and other chamber music, and vocal music from song to oratorio. Many of his works were inspired by the art of William Blake.