This is a list of music-related events in 1803.

This article relies largely or entirely on a single source. (March 2019)

• 5 April – first performance of Beethoven's Third Piano Concerto^[1]
• 26 December – Haydn performs his last public concert, conducting The Seven Last Words of Christ

• Ludwig van Beethoven
  • Violin Sonata No. 7 published, composed between 1801 and 1802
  • Violin Sonata No. 9
  • Trio in E-flat major, Op. 38
  • 3 Marches, Op. 45
  • Piano Sonata No. 21 "Waldstein" started^[vague], Op. 53
  • Symphony No. 3 "Eroica", Op. 55
  • Christus am Ölberge, oratorio, Op. 85
  • Das Glück der Freundschaft, Op. 88
  • 10 Variations on 'Ich bin der Schneider Kakadu', Op. 121a
  • Minuet, WoO 82
• Johann Evangelist Brandl – Symphony in D major, Op. 25
• Bernhard Henrik Crusell – Concerto for Clarinet No. 3 in B-flat major
• Franz Danzi
  • Preiss Gottes, P.48
  • Sextet in E major, Op. 15
• Jan Ladislav Dussek – Piano Quartet in E-flat Major Op. 53 or 56
• Anton Eberl – Symphony in E-flat major, Op. 33
• Joseph Haydn
  • unfinished String Quartet in D minor, Op. 103
  • 6 Trios, Liv. 1
• Jeremiah Ingalls – "Northfield"
• Franz Krommer
  • Concerto No.1 for 2 Clarinets, Op. 35
  • Clarinet Concerto No.1, Op. 36
  • Concerto for Oboe in F Major (Op. 37)
  • Symphony No. 2, Op. 40
• Niccolo Paganini
  • Sonata concertata, MS 2
  • Grande sonata, MS 3
  • Le streghe, Op. 8
• Georg von Pasterwitz – 300 Themata und Versetten, Op. 4
• Ignaz Pleyel – 3 Keyboard Trios, B.474–476
• Pierre Rode – Violin Concerto No.7 in A minor, Op. 9
• Bernard Romberg
  • Cello Concerto No.1, Op. 2
  • 3 Grand Sonatas, Op. 5
• Antonio Salieri – Gesù al limbo für Soli, vierstimmigen Chor und Orchester
• Louis Spohr – Violin Concerto in C Major
• Giovanni Battista Viotti –
  • Trio for 2 Violins and Cello in E major
  • Trio for 2 Violins and Cello in G major
• Joseph Wölfl – Symphony in G minor, Op. 40

• Gaetano Andreozzi – Il trionpho di Alessandro
• Luigi Cherubini – Anacréon
• Anton Fischer – Die Entlarvten
• Ferdinando Paër – Sargino
• Giovanni Paisiello – Proserpine
• Antonio Salieri – Die Hussiten vor Naumburg

• January 1 – Carolina Brunström, ballerina (d. 1855)
• January 6 – Henri Herz, pianist and composer (died 1888)
• February 17 – Joseph-Philippe Simon, librettist and actor (died 1891)
• April 2 – Franz Lachner, Bavarian composer/conductor (died 1890)
• April 12 – Anton Wilhelm von Zuccalmaglio, lyricist and composer (died 1869)
• May 12 – Alexandre Montfort, French composer (died 1856)
• June 24 – George James Webb, composer (died 1887)
• June 30 – Thomas Lovell Beddoes, librettist and poet (died 1849)
• July 8 – Julius Mosen, librettist and lawyer (died 1867)
• July 19 – Franz von Kobell, lyricist and mineralogist (died 1882)
• July 20 – Jakob Zeugheer, composer and violininst (died 1865)
• July 24 – Adolphe Adam, French composer (died 1856)
• July 25 – Ferdinand Beyer, arranger and composer (died 1863)
• September 4 – Anna Nielsen, mezzo-soprano (died 1856)
• September 12 – Auguste Brizeux lyricist and artist (died 1858)
• October 11 – Prosper Mérimée, lyricist and writer (died 1870)
• December 5 – Fyodor Tyutchev, lyricist and poet (died 1873)
• December 11 – Hector Berlioz, composer (died 1869)
• date unknown – Jan z Hvězdy, lyricist and writer (died 1853)

• January 17 – Franz Ignaz von Beecke, composer (born 1733)
• January 18 – Sylvain Maréchal, lyricist and writer (born 1750)
• January 28 – Karl von Marinelli, theatre manager (born 1745)
• February 5 – Giovanni Battista Casti, librettist and poet (born 1724)
• February 6 – Gasparo Angiolini, dancer, choreographer and composer (born 1731)
• February 16 – Giovanni Punto, composer and horn player (born 1746)
• February 18 – Johann Wilhelm Ludwig Gleim, lyricist and poet (born 1719)
• March 14 – Friedrich Gottlieb Klopstock, lyricist and poet (born 1724)
• May 8 – John Joseph Merlin, clock- and musical-instrument-maker and inventor (born 1735)
• June 6 – Louis Gallodier, dancer and choreographer (born c.1734)
• July 5 – William Jackson, composer and organist (born 1730)
• July 14 – Esteban Salas y Castro, Cuban composer (born 1725)
• August 29 – Giovanni de Gamerra, librettist and cleric (born 1742)
• September 5 – François Devienne, composer (born 1759)
• September 17 – Franz Xaver Süssmayr, composer (born 1766)
• September 21 – John Christopher Moller, composer and music publisher (born 1755)
• October 7 – Pierre Vachon, composer (born 1738)
• October 8 – Vittorio Alfieri, librettist and dramatist (born 1749)
• December 18 – Johann Gottfried Herder, lyricist and philosopher (born 1744)
• date unknown
  • Johann Becker, organist and composer (born 1726)
  • Johann Christoph Kellner, organist and composer (born 1736)