The Pioneer Zephyr (unofficially the "Silver Streak") is a dieselpowered trainset built by the Budd Company in 1934 for the Chicago, Burlington & Quincy Railroad (CB&Q), commonly known as the Burlington Route. The trainset was the second internal combustionpowered streamliner built for mainline service in the United States (after the Union Pacific Railroad's M10000), the first such train powered by a diesel engine, and the first to enter revenue service.

It is now on display at the Museum, of Science and Industry in Chicago.