Paul de Schlözer (1841 or 1842 – 1 July 1898) was a Polish pianist and teacher of German origin. He was probably also a composer, although only two works have been attributed to him, and both may have been written by the Polish composer Moritz Moszkowski.
Little is known about Schlözer's life. He worked as a pianist and accompanied the Spanish violinist Pablo de Sarasate and his own brother, the violinist Theodor (Fyodor) de Schlözer. From 1879 he taught at the Warsaw Institute of Music, succeeding the retired Juliusz Janotha. Ignacy Paderewski mentioned Schlözer in his letters, sometimes referring to him as “Mr. Paul” and “Pablito.”
Around 1892 Schlözer became a professor at the Moscow Conservatory; the musicologist Leonid Sabaneyev was among his best-known pupils. On 3 February 1894, he performed Chopin's Sonata for Cello and Piano at the Conservatory hall with the Czech cellist Hanuš Wihan. His niece Tatiana Schlözer became the second, de facto wife of Alexander Scriabin, while her brother Boris de Schlözer became a noted music critic.
Schlözer is known as a composer chiefly through two piano études, Op. 1. A frequently repeated claim says that Sergei Rachmaninoff used the second étude, in A-flat major, as a daily warm-up, though at least one source describes this story as a legend. The étude was recorded by Vera Timanova in 1907, Jorge Bolet, Stephen Hough, and Eileen Joyce; Joyce's 1941 recording has been regarded as unsurpassed.
Some researchers doubt that Schlözer wrote the études. According to a circulating story, Moszkowski lost them to Schlözer in a card game, after which Schlözer published them under his own name. The second étude resembles Moszkowski's Étude No. 11 from the 15 Études de Virtuosité, Op. 72, also in A-flat major, although that resemblance may itself have given rise to the attribution legend.