| Static Image Name: | St Leonards South Ormsby.jpg |
| Static Image Caption: | St Leonard's Church, South Ormsby |
| Country: | England |
| Official Name: | South Ormsby |
| Coordinates: | 53.2614°N 0.0519°W |
| Shire District: | East Lindsey |
| Shire County: | Lincolnshire |
| Region: | East Midlands |
| Constituency Westminster: | Louth and Horncastle |
| Post Town: | Louth |
| Postcode District: | LN11 |
| Postcode Area: | LN |
| Os Grid Reference: | TF369757 |
| London Distance Mi: | 125 |
| London Direction: | S |
South Ormsby, sometimes called South Ormesby, is a village in the East Lindsey district of Lincolnshire, England. It is situated 1miles west from the A16 road, 7miles south from Louth and 7 miles north-east from Horncastle. With the nearby hamlet of Ketsby, it forms the civil parish of South Ormesby with Ketsby. The population is included in the civil parish of Brinkhill.
The 15th-century church of St Leonard's is approached by a short climb up a path next to the old school house.
Ormsby Hall, built by James Paine in 1752, stands in a wooded parkland complete with lake.
The village has a public house, the Massingberd Arms, and a motor repair garage.
The Greenwich Prime Meridian line passes through the village.