Michael John Harrison, known for publication purposes primarily as M. John Harrison, is an English author and literary critic. His work includes the Viriconium sequence of novels and short stories (1971–1984), Climbers (1989), and the Kefahuchi Tract trilogy, which consists of Light (2002), Nova Swing (2006) and Empty Space (2012).

Nova Swing is a science fiction novel by M. John Harrison published in 2006. It takes place in the same universe as Light. The novel won the Arthur C. Clarke and Philip K. Dick Awards in 2007.