The Nelthorpe baronetcy, of Grays Inn in the City of London, was a title in the baronetage of England. It was created on 10 May 1666 for John Nelthorpe. The fifth baronet was High Sheriff of Lincolnshire in 1741, the sixth baronet High Sheriff in 1767, the seventh baronet in 1800 and the eighth baronet in 1842. The title became extinct on the death of the last in 1865.
The family seat was Scawby Hall, Scawby, Lincolnshire.