Treaty of Viborg
The Round Tower in Vyborg, in which an agreement was signed on February 28, 1609  | |
| Type | Union agreement | 
|---|---|
| Location | Round Tower, Viborg, Sweden (now in Russia) | 
| Signatories | |
The Treaty of Viborg was a package of 7 documents signed in Viborg during 1609 between Sweden and Russia on the provision by Sweden of military assistance to the government of Vasily Shuisky.