The Niagara Rainbow, known as the Empire State Express before 1976, was an American passenger train service operated by Amtrak between New York City and Detroit via Buffalo and Southwestern Ontario in Canada.

Before that it was one of the trains on the Empire Corridor, making a daily run between New York's Grand Central Terminal and Buffalo.

[2] A day train, the Empire State Express carried no sleeping accommodations, but did run with a baggage car and diner.

In 1978, several state governments proposed replacing the Niagara Rainbow and its Chicago—Cleveland—New York counterpart, the Lake Shore Limited, with a single train.

It operated as a once-weekly additional frequency of the Maple Leaf, departing New York on Friday night and returning on Monday morning.