Theydon Garnon is a village and civil parish in the Epping Forest district, in the county of Essex, England.

[3] A weekly market and annual fair was granted to Theydon Garnon in 1305.

Epping Union Workhouse was in Theydon Garnon; it and Epping station also opened within the parish in 1865, but was included in the newly formed Epping Urban District in 1896, along with the village of Coopersale and the hamlets of Coopersale Street, and Fiddler's Hamlet.

[3] The village contains an Anglican parish church, dating back to the 13th Century and dedicated to All Saints.

Nearby settlements include the town of Epping, the large village of Theydon Bois, the small village of Theydon Mount and the hamlets of Hobbs Cross and Fiddlers Hamlet.