Laurens Hammond (1894–1973) was an American inventor and engineer whose tonewheel technology created one of the most recognizable sounds in 20th-century music.

Hammond originally developed synchronous motors for clocks; in 1934 he patented the tonewheel generator — a stable electromechanical source of sine waves — and applied it to the Model A organ, marketed as a compact alternative to pipe organs for churches and homes.

The Model B-3 (1954) became the definitive Hammond organ: nine drawbars per manual, a percussion circuit for attack emphasis, and the famous waterfall keybed favored by jazz and gospel players. Paired with Leslie rotating speakers, the B-3 defined Hammond tone on records by Jimmy Smith, Booker T. Jones, Jon Lord of Deep Purple, and countless rock bands.

Hammond also invented the Novachord (1939), an early polyphonic synthesizer precursor, and the Solovox monophonic attachment. His company produced organs, chimes, and rhythm units until financial pressures led to sale of the business; tonewheel instruments remain icons of soul, jazz, prog rock, and liturgical music worldwide.

Notable products: Hammond Model A, B-3, C-3, Novachord, Solovox, tonewheel generator.