Bartolomeo Giuseppe Antonio Guarneri, del Gesù (21 August 1698 – 17 October 1744) was an Italian luthier from the Guarneri family of Cremona. He rivals Antonio Stradivari (1644–1737) with regard to the respect and reverence accorded his instruments, and for many prominent players and collectors his instruments are the most coveted of all. Instruments made by Guarneri are often referred to as Del Gesùs.
Guarneri is known as del Gesù (literally "of Jesus") because his labels after 1731 incorporated the nomina sacra, I.H.S. (iota-eta-sigma) and a Roman cross. His instruments diverged significantly from family tradition, becoming uniquely his own style. They are considered equal in quality to those of Stradivari, and claimed by some to be superior. Guarneri's violins often have a darker, more robust, more sonorous tone than Stradivari's. Fewer than 200 of Guarneri's instruments survive. They are all violins, although one cello bearing his father's label, dated 1731, seems to have been completed by del Gesù. The quality and scarcity of his instruments have resulted in sale prices in excess of $10 million USD.
- Wibberley, Leonard (1976). Guarneri: Violin Maker of Genius. London; England: Macdonald & Jane's. ISBN 0-356-08377-2.
- William, Henley (1969). Universal Dictionary of Violin & Bow Makers. Brighton; England: Amati. ISBN 0-901424-00-5.
- Italian Violin Makers, Karel Jalovec, Paul Hamlyn, London, 1964.