The Otago and Southland Regiment is a Territorial Force unit of the New Zealand Army. It was originally formed in 1948 by the amalgamation of two separate regiments:
- Otago Regiment
- Southland Regiment
In turn, those two regiments were the heirs of the original 4th (Otago Rifles) Regiment, 10th (North Otago) Regiment, 8th (Southland Rifles) Regiment and 14th (South Otago) Regiment formed in the early 1900s.