Largely self-taught as a pianist, Gieseking was born in Lyon, France, on November 5, 1895; with his family (his father was a distinguished doctor and entomologist), he traveled in France and Italy until he enrolled at the Hannover Conservatory, where he came under the tutelage of Karl Leimer, making his debut in 1915.
Gieseking was drafted into the German army a year after his first public performance but escaped combat by performing in his regimental band. After the war, he undertook the the life of a working musician, accompanying singers and instrumentalists, playing in chamber music ensembles, and working as an opera coach. He could hardly avoid the heady artistic atmosphere of postwar Germany, and he became an advocate of new music, playing works by Schoenberg, Busoni, Hindemith, Szymanowski, and Pfitzner, whose Piano Concerto he premiered under Fritz Busch in 1923. Subsequent debuts in London (1923), the United States (1926, Aeolian Hall, New York), and Paris (1928) were highly acclaimed, with audiences and critics responding enthusiastically to Gieseking's subtle shadings and contrapuntal clarity. The Second World War brought controversy to Gieseking: like many other artists who remained in Germany during hostilities, he was accused of collaborating with the Nazis. His 1949 Carnegie Hall engagements caused such an uproar that they had to be cancelled; but he was eventually cleared of all charges by an Allied court in Germany. His concert career resumed with the success it had formerly enjoyed. To this activity he added a heavy schedule of recording, committing to disc the complete solo piano music of Mozart and the Beethoven concertos, as well as complete sets of Debussy's and Ravel's piano works. At the time of his death in London (October 26, 1956), Gieseking was engaged on a project to record all the Beethoven piano sonatas. His recordings of Debussy and Ravel are regarded as benchmarks for every subsequent performer.
Gieseking's autobiography, So wurde ich Pianist, was published posthumously in 1963; it seems never to have been translated into English.