John Field (26 July 1782 [?], baptized 5 September 1782 – 23 January 1837) was an Irish pianist, composer, and teacher. He was born in Dublin into a musical family, and received his early education there. The Fields soon moved to London, where Field studied under Muzio Clementi. Under his tutelage, Field quickly became a famous and sought-after concert pianist; together, master and pupil visited Paris, Vienna, and St. Petersburg. The Russian capital impressed Field so much that he eventually decided to stay behind when Clementi left, and from about 1804 was particularly active in Russia.

Field was very highly regarded by his contemporaries and his playing and compositions influenced many major composers, including Frédéric Chopin, Johannes Brahms, Robert Schumann, and Franz Liszt. He is best known today for originating the piano nocturne, a form later made famous by Chopin, as well as for his substantial contribution, through concerts and teaching, to the development of the Russian piano school.