Hatto grew up in a music-loving family in England. She studied with Serge Krish, a former student of Busoni, in the 1940s and sought advice from Alfred Cortot, Sviatoslav Richter and Clara Haskil, among others. She studied composition with Paul Hindemith, Nadia Boulanger and Matyas Seiber.

She made her London debut in the early 1950s and played extensively in Britain, often with programs unusual for the time, such as all-Liszt recitals. She also made three tours of Poland.

Hatto stopped playing in public in 1976 due to an ongoing fight with cancer, according to the August 2005 Boston Globe article, which reported that she was criticized by journalists for her appearance and had once been told that it is ''impolite to look ill."

She continued to record prolifically, however. Her more than 119 recordings on the British label Concert Artists include complete cycles of Beethoven, Mozart and Prokofiev sonatas; Rachmaninoff, Tchaikovsky, Brahms and Mendelssohn concertos; and the complete works of Chopin. She was also one of the few pianists to have recorded the complete Godowsky Chopin Studies.

Her recordings never achieved mainstream success, but, the Globe wrote, "Best of all is her musical imagination, which finds original things to say about the most familiar music. There is sadness, as well as glitter, in the Chopin Waltzes, for example; an operatic vocality and fluidity in her Mozart Sonatas; amazing individual characterizations of each of the Brahms Paganini Variations, made possible by an equally amazing pianistic command. Not one of the recordings that I have heard sounds hastily or carelessly prepared; not one of them lacks some special insight."

The cause was cancer, according to BBC Music Magazine. No date of death was given in the obituary, though the Wikipedia entry on Hatto gives the date as June 30.