Thornton, or Thornton by Horncastle, is a village in the civil parish of Roughton, in the East Lindsey district of Lincolnshire, England.

It is situated on the B1191 road, 1 mile (1.6 km) west from the A153, and 1.5 miles (2.4 km) south-west from Horncastle town centre.

[1] On 1 April 1987 the parish was abolished and merged with Roughton.

[2] The village is mentioned in the 1086 Domesday Book, with 19 households and Robert the Bursar as Lord of the Manor.

[3] The greenstone parish church is dedicated to Saint Wilfrid and is a Grade II listed building dating from the 15th century and restored in 1890 by Ewan Christian.