The SS Buckaroo Banzai was a Terran BBI-993-type starship that was in service in the mid-22nd century.

In 2137, Captain John Whorfin was the commanding officer of this ship. In that year, the ship was launched from Earth for a mission to Planet 10 (DIM-8). (TNG: "Up The Long Ladder", okudagram)

This starship was only mentioned in writing.
The name of this ship was mentioned in a list of ships that were launched from Earth, with destinations in or near to the Ficus sector, between the years 2123 and 2190. This list was displayed on Jean-Luc Picard's desk monitor in his ready room aboard the USS Enterprise-D. A legible version of the okudagram first appeared in the reference book, Star Trek: The Next Generation - The Continuing Mission. The list became legible to viewers with the remastered "Up The Long Ladder”.
Buckaroo Banzai, BBI, John Whorfin, and Planet 10 (DIM 8) are in-joke references to 1984's The Adventures of Buckaroo Banzai Across the Eighth Dimension!. While working at 20th Century Fox in the 1980s, Denise Okuda (née Denise Tathwell) was the director of the Buckaroo Banzai Fan Club.