The control of seed dormancy by ethylene has been well studied, but the molecular mechanisms are not fully understood. Here, we report the cloning and characterization of the mutant reduced dormancy 3 (rdo3). We demonstrated that rdo3 is a loss of function mutant of the ethylene receptor ETHYLENE RESPONSE 1 (ETR1). ETR1 controls seed dormancy partially through the DELAY OF GERMINATION 1 (DOG1) pathway. Molecular and genetic studies demonstrated that ETHYLENE RESPONSE FACTOR 12 (ERF12) is involved in the regulation of seed dormancy downstream of ETR1. ERF12 can interact with TOPLESS (TPL) and genetically requires TPL to function. ERF12 and TPL can repress the expression of DOG1 by occupying its promoter. Thus, we identified the dormancy pathway ETR1-ERF12/TPL-DOG1 and provided a mechanistic insight on the regulation of seed dormancy by linking the ethylene and DOG1 pathways.