Elachista sylvestris is a moth of the family Elachistidae. It is found in the United States, where it has been recorded from Maine, Ohio, Illinois and New Hampshire.
The wingspan is 8âÂÂ8.5 mm. Adults have been recorded on wing from May to July.
The larvae feed on Poa sylvestris. They mine the stem leaves of their host plant. Mining larvae can be found in April and early May.