| Enno III | |
|---|---|
| Count of West Frisia | |
 Enno III, Count of West Frisia | |
| Reign | 1599–1625 |
| Predecessor | Edzard II |
| Successor | Rudolf Christian |
| Born | 30 September 1563 Aurich |
| Died | 19 August 1625 (aged 61) Leerort |
| Spouse | Walburgis, Countess of Rietberg Anna of Holstein-Gottorp |
| House | Cirksena |
| Father | Edzard II, Count of East Frisia |
| Mother | Catherine of Sweden |
Enno III of Ostfriesland or Enno III of East Frisia (30 September 1563, Aurich – 19 August 1625) was a Count of Ostfriesland from 1599 to 1625 from the Cirksena family. He was the elder son of Count Edzard II of Ostfriesland and his wife Princess Katarina of Sweden, eldest daughter of King Gustav I of Sweden.
In 1602 Enno III's troops laid siege to Emden, without success; On 8 April 1603 Enno had to sign the Treaty of The Hague in which he not only accepted the presence of a Dutch garrison in Emden, but agreed to pay the costs for the Dutch garrison. In 1609 the conflict broke out again; the Emders were victorious in a skirmish at Greetsiel and temporarily occupied the Count's residence at Aurich. In 1611 the Dutch garrisoned troops in Leerort. On 24 May the Accord of Osterhusen was signed, which limited the sovereignty of the Count of East Frisia, stated the rights of the Estates (including Emden) and legitimised the Dutch garrison in Leerort.