Dr. Langford was a Federation archeologist in the 24th century. She was an acquaintance of Starfleet Captain Jean-Luc Picard, and in 2369 she asked the captain to accompany her to an excavation on Suvin IV. (TNG: "Rascals")

This character was only mentioned in dialogue.
Langford was named after a woman Ronald D. Moore was dating at the time. He remarked, "She wasn't a fan and we stopped going out soon after, so I don't think she ever saw it!" (Star Trek: The Next Generation Companion)