The Lightning is an American sailing dinghy that was designed by Olin Stephens of Sparkman & Stephens, as a one-design racer and first built in 1938. An accepted World Sailing class, the boat is one of the most popular one-design sailing classes in the United States and is also raced in several other countries. The design was developed into a smaller boat, as a trainer for the Lightning, the Blue Jay in 1947.