The term Dutch referred to anything originating from the Earth country of the Netherlands, including its people and its language.
Benedict de Spinoza was a 17th century Dutch philosopher. (TOS: "Where No Man Has Gone Before"; TNG: "Ethics")
During the 19th century, the Dutch painter Vincent van Gogh was one of the most influential artists on Earth. (TNG: "The Most Toys", DS9: "Second Sight")
During a discussion between Deanna Troi and Samuel Clemens in 2369, Clemens, who assumed that the nature of the USS Enterprise-D was one of "military conquest" rather than "exploration", mused that the same was said by all conquerors, including the Spanish, Dutch, and Portuguese, who revered themselves as also being "explorers". (TNG: "Time's Arrow, Part II")
Noted Dutch actors in Star Trek include Famke Janssen and Carel Struycken.