| Siege of Theodosia | 
|---|
| Part of Bosporan Expansion Wars | 
| Date | c. 360 BC | 
|---|
 | Location | Theodosia, Bosporus  | 
|---|
 | Result | 
 Bosporan Victory 
- Annexation of Theodosia into Bosporan hegemony.
 
  | 
|---|
 
  | 
| Belligerents | 
|---|
| 
Theodosia | 
Bosporan Kingdom | 
| Commanders and leaders | 
|---|
| 
Unknown | 
Leukon I | 
| Strength | 
|---|
| 
Unknown | 
Unknown | 
| Casualties and losses | 
|---|
| 
Medium | 
Low | 
The siege of Theodosia in c. 360 BC was the third and final siege by the Bosporan Kingdom under Leukon I against the city of Theodosia, a probable colony of Heraclea Pontica, who had aided the city in two previous sieges.