ESB engineers are working to restore power to 383 homes in Letterkenny tonight.
Service was cut around 9.40m to houses in Cullion.
ESB staff say they are working to fix the fault and hope to restore power around 1.15am tonight.
Staff say this is an estimated restoration time.
It follows power cuts in west Donegal earlier in the evening where faults have been fixed.
Around 4,000 homes lost power there for a time.