The Lilly B is a ferry owned by Bustins Island, Maine, United States.

[2] The vessel was designed by naval architect Al Spalding and built by Bradley Simmons.

[2] The ferry has a capacity of 44 passengers, and it is not permitted to carry propane or gasoline as baggage.

[4] Archie Ross formerly captained the ferry for over fifty years,[5] and the island's public landing is now named for him.

In the high season (mid-June to early September), the Lilly B runs four round-trips daily on weekdays and once on weekends.