New London Union Station is a railroad station on the Northeast Corridor located in downtown New London, Connecticut, United States. Union Station is a station stop for most Amtrak Northeast Regional trains and all CTrail Shore Line East commuter rail trains, making it the primary railroad station in southeastern Connecticut. It serves as the centerpiece of the Regional Intermodal Transit Center, with connections to local and intercity buses as well as ferries to Long Island and Fishers Island, New York, and Block Island, Rhode Island. The station has one side platform and one island platform serving the two-track Northeast Corridor; the latter platform also serves a siding track that connects to the New England Central Railroad mainline.

The Northeast Regional is an intercity rail service operated by Amtrak in the Northeastern and Mid-Atlantic United States. In the past it has been known as the NortheastDirect, Acela Regional, or Regional. It is Amtrak's busiest route, carrying 9,163,082 passengers in fiscal year (FY) 2023. The Northeast Regional service received more than $787.7 million in gross ticket revenue in FY 2023.