Stigmella unifasciella is a moth of the family Nepticulidae. It is found in the United States in Kentucky, Ohio, Maryland, Illinois, Texas and Massachusetts.
The wingspan is 4.5-7.4 mm. There are possibly two generations per year. Adults have been collected in mid-June in Ohio and in late July on Plummers Island in Maryland.
The host plant is unknown, but might be a Quercus species.