Ashby by Partney is a hamlet in the East Lindsey district of Lincolnshire, England. It is located to the south of the A158, 2 miles (3.2 km) east of the town of Spilsby. It neighbours the village of Partney, and forms part of the civil parish of Ashby with Scremby.
The settlement is recorded in the Domesday Book as consisting of 26 households, with Earl Hugh of Chester as Lord of the Manor.
The church, dedicated to Saint Helen, was built of pale orange brick in 1841, on the site of an earlier church. In 1892 C Hodgson Fowler restored the interior, retaining the 14th-century font. It is a Grade II listed building.