Piemontesi was born in Locarno, in Switzerland's Italian-speaking Ticino canton, on July 7, 1983, and grew up in nearby Tenero. Showing talent as a child, he made his concert debut in 1994 and enrolled at age 15 in classes at the Lugano University of Music. He moved on to the Hannover University of Music and Drama (now the University of Music, Drama, and Media) in Germany after graduating from high school in 2002. There, he studied with Arie Vardi, and he later took lessons from Alfred Brendel, Alexis Weissenberg, and Murray Perahia. Triple breakthroughs paved the way for Piemontesi's concert career: he won the Queen Elisabeth Competition in Brussels in 2007 and the prestigious Borletti-Buitoni Trust Fellowship in 2009, and he was named a BBC New Generation Artist for 2009-2011. Since then, Piemontesi has been a fixture of symphonic seasons in Europe and the U.S., appearing as a concerto soloist with the likes of the London Philharmonic, the Leipzig Gewandhaus Orchestra, and the Cleveland Orchestra. He has given recitals at the Musikverein and Konzerthaus in Vienna, Carnegie Hall and Avery Fisher Hall in New York, and at Wigmore Hall in London, among many other venues. At Wigmore Hall, he presented a complete cycle of Mozart's piano music beginning in 2016, and he began a similar cycle devoted to Schubert in 2019. Although he often plays the music of Mozart, Beethoven, and the early Romantics, he is an enthusiastic exponent as well of Brahms, Debussy, Ravel, and other late Romantic and early 20th century composers. Piemontesi has performed chamber music with violinist Renaud Capuçon, clarinetist Jörg Widmann, and the Emerson String Quartet. Piemontesi is a frequent guest at festivals, including the BBC Proms, the Aix-en-Provence Festival, and the Mostly Mozart Festival. Since 2013, he has been the artistic director of the Settimane Musicali di Ascona, Switzerland.
Piemontesi has recorded steadily through the 2010s and 2020s for Naïve, Orfeo, Linn, and other labels. In 2019, he issued a recording for PentaTone of Schubert's late piano sonatas, and the following year, he joined cellist Daniel Müller-Schott for an album of the cello sonatas of Brahms. ~ James Manheim, Rovi