Lupita Nyong'o as Sitina Essayas Natnael
Sitina Essayas Natnael was a Starfleet Officer serving during the 24th century.
She traced her ancestry to Earth's Ethiopian population.
After Operation Return she was assigned to the 101st Tactical Wing as Nikolas Stone's Chief of Staff. Prior to that, she had served as part of the Command Department on Deep Space 7 and aboard the USS Princeton. ("Familiar Faces")