Kelby is both a surname and a given name. Notable people with the name include:
Coordinates: 52°57′40″N 0°30′21″W / 52.960976°N 0.505892°W / 52.960976; -0.505892
Kelby is a hamlet in the civil parish of Heydour, in the South Kesteven district of Lincolnshire, England. It lies 5 miles (8 km) south-west from Sleaford, 9 miles (14 km) north-east from Grantham and 3 miles (5 km) south-east from Ancaster. Kelby, with Heydour, Aisby, Oasby and Culverthorpe are the five hamlets within Heydour parish.
Kelby church is dedicated to St Andrew and is a chapelry of Heydour. Its tower was rebuilt in 1881 after a collapse. The church basement is Norman and the font Early English, with pews originally from the chapel at nearby Grade II listed Culverthorpe Hall.
A chapel for Primitive Methodists was established in 1859.