The Nottinghamshire and Derbyshire trolleybus system once linked the city of Nottingham, in the county of Nottinghamshire, England, with Ripley, in the neighbouring county of Derbyshire. Opened on , it replaced the Nottinghamshire and Derbyshire tramway, between the same termini.
By the standards of the various now-defunct trolleybus systems in the United Kingdom, the system was a small and short-lived one, with a total of three routes, and a maximum fleet of 32 trolleybuses. It was closed relatively early, on .
Three of the former Notts & Derby system trolleybuses are now preserved, one of them at the Trolleybus Museum at Sandtoft (although not currently on display), and the other two in a private collection in Boughton, Nottinghamshire.
The city of Nottingham was also served by the Nottingham trolleybus system, in operation between 1927 and 1966. A Derby trolley bus network also existed from 1932 to 1967, having also taken over from tramcars. It finished when extensive roadworks made alterations to the overhead wiring uneconomic.