Who was the first Klingon to serve in Starfleet?

The first Klingon to serve in Starfleet was Worf. He was born on Qo'noS, orphaned in the Romulan attack on Khitomer, and raised by the human Rozhenko family after being rescued by the Federation.

Worf entered Starfleet Academy in 2357 and graduated in 2361 as an ensign. His choice was unusual: many Klingons viewed Starfleet service as dishonorable or insufficiently martial, while Worf saw it as a way to uphold both Federation duty and Klingon honor.

He first became a major Star Trek character in The Next Generation, serving as the Enterprise-D's security chief and tactical officer. He later joined Deep Space Nine, where he became strategic operations officer and served aboard the USS Defiant. Michael Dorn portrayed him across multiple series and films.

Alexander is Worf's son, not the first Klingon Starfleet officer. Martok is a prominent Klingon general and chancellor, while Guinan is an El-Aurian civilian associated with Starfleet crews. Worf's status as the first Klingon Starfleet officer is part of his established backstory.