As its name implies, the Mennello Museum is focused entirely on the contributions of American folk artists, most of whom were primarily active during the 20th century.  The collection began in 1998 with a donation of works of American folk artist Earl Cunningham, by Marilyn and Michael Mennello, to the City of Orlando.  The museum has continued to collect and exhibit works by some of the most prominent American artists, in addition to hosting a number of traveling exhibitions.  Notable past exhibitions have included a collection of works by Savannah barber and wood sculptor Ulysses Davis, and the extensive personal collection of Edward Wales Root.

The Mennello Museum is located within Loch Haven Park, a sort of “cultural reserve” that is also home to the Orlando Museum of Art, Orlando Philharmonic Orchestra, and Orlando Repertory and Shakespeare Theaters.  The Museum facility is located on Lake Formosa, which is surrounded by a trail for hiking and biking; situated along the trail is an extended sculpture garden displaying works of American sculpture for enjoyment in an idyllic outdoor environment.

The Museum also hosts the annual Orlando Folk Festival, which features music, dance, storytelling, and demonstrations of folk art and craft over two days each February.  The Festival is free to the public.