The Optimist is a small, single-handed sailing dinghy intended for use by children up to the age of 15. Modern boats are made of fiberglass according to the One-Design principle meaning all boats look and weigh the same. It is one of the most popular sailing dinghies in the world, with over 150,000 boats officially registered with the class and many more built but never registered.

The weight span of an optimist sailor should be between 30 kg to 55 kg. This allows the sailor to handle the boat in up to 30 knots of wind even if the boat is not built for big waves.  The only way of emptying the boat from water is via bailers. This makes the optimist unique as it is the only class with this limitation.
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In Sweden, the optimist is widely used by children as an introduction to sailing but there is also a community of elite sportsmen and women.  In comparison to most other sports, the Optimist Class requires slightly less physical prowess but emphasizes the need for a combination of endurance and intelligence.