Long Green is an unincorporated community in Baltimore County, Maryland, United States.

The community was founded by Lancaster County Amish, but few settlers moved to the area because Maryland was a slave state at the time.

[4] One of the oldest buildings in Long Green is the Wilson United Methodist Church, built in 1892 in the Gothic Revival style.

A previous Methodist meeting house was built in 1839 on land donated by George Wilson, for whom the present church is named.

In 1787, noted Methodist leader Francis Asbury preached in the Long Green farmhouse of Wilson's great-uncle.