The measuring instruments belonging to Sir Robert Dudley, Duke of Northumberland, form a homogeneous collection. They were bequeathed to the Medici by Dudley himself in 1649. They remained the personal property of the Grand Duke until 1654, and were then placed in the Sala delle Matematiche of the Uffizi, which housed many of the astronomical and mathematical instruments in the Grand Duke's collection.

The Dudley Collection includes precious nautical instruments embodying noteworthy innovations: tide calculators, theodolites, protractors, devices for measuring the positions of the stars, windroses, quadrants, and compasses. Many had been designed by Dudley himself and made by his trusted craftsman Charles Whitwell; others are signed by famous English makers such as James Kynvyn, Thomas Gemini, Augustine Ryther, and Humphrey Cole. The Dudley Collection also contains instruments of non-English provenance, such as the Portuguese mariner's astrolabe, of the kind typically used in voyages of exploration, and a fine Flemish astrolabe, probably built by the great geographer and cartographer Gerard Mercator.