Tiburon was an inhabited planet. This was the homeworld for the Tiburonians, a warp-capable species.
In 2149, Doctor Phlox attended an IME conference on Tiburon, where he briefly met a member of the Mazarite delegation. Unknown to him at the time, this member was actually a Klingon expert in metagenic research, named Dr. Antaak. The Klingons were not invited to the conference. (ENT: "Affliction")
Zora was an infamous scientist on Tiburon, known for her cruel and inhumane experiments on humanoid subjects to test the body chemistry of subject tribes. (TOS: "The Savage Curtain")
Tiburon was the former home of Dr. Sevrin in the mid-23rd century, where he studied to become an expert in the fields of acoustics, electronics and communications. (TOS: "The Way to Eden")
T'Lor, a Tiburonian, served as a Starfleet science officer on Deep Space 9 in the early 2370s. He was killed by the Jem'Hadar on Torga IV. (DS9: "The Ship")
T'Lor was established in the script of "The Ship" to be a Tiburonian.