I Soft Machine are an English musical group formed in 1966 in Canterbury, Kent. The name comes from the 1961 novel of the same name by William S. Burroughs, published in Italian under the title The soft machine. Disbanded in 1984, since 1999 some former members of the group have formed satellite bands, and in 2015 the last of these groups, Soft Machine Legacy, resumed the original Soft Machine name.

They were one of the leading formations of the Canterbury scene and one of the pioneering bands of progressive rock and, together with Pink Floyd and Tomorrow, represented the first original wave of experimentation and psychedelia in London. Their musical style has evolved over the years and has been based on fusion since the early 1970s.