T'Pol (/tɪˈpɒl/) is a fictional character in the Star Trek franchise. Portrayed by Jolene Blalock in the series Star Trek: Enterprise, she is a Vulcan who serves as the science officer aboard the starship Enterprise (NX-01). She appeared in all 98 episodes of "Enterprise" and reprised her role in one episode of Star Trek: Lower Decks.

Series producer Rick Berman said they originally intended that a younger version of T'Pau would be the Vulcan officer serving on the titular starship in Star Trek: Enterprise. Instead, after determining there were legal difficulties in using the original series character, the producers created T'Pol. Brannon Braga said the idea was dropped to avoid having to deal with any legal issues, and that T'Pol was simply easier to pronounce. Marjorie Monaghan, Blalock, and an unnamed actress were the final three considered for the role. By that time, Berman said they had seen hundreds of actresses, and they struggled to find a "beautiful woman who can act and doesn't want to go right into feature films". Casting director Ron Surma had Blalock in mind from the beginning but her agents said she was not interested. Braga thought Blalock was perfectly cast, "We wanted a sexy Vulcan, a Kim Cattrall-type, and we definitely got that".

T'Pol is the first Vulcan officer to serve a prolonged term on a human vessel. T'Pol served aboard the Enterprise for 10 years (2151–2161). To compare, the previous record was just 10 days. As a sub-commander serving the Vulcan High Command, she was stationed aboard the Enterprise in April 2151, as an observer to Captain Jonathan Archer and his crew, who the High Command insisted, were not ready for interstellar space exploration. After the success of the Enterprise's initial mission led to the vessel being given an extended exploration mandate, T'Pol requested to stay aboard.

T'Pol remained aboard the Enterprise despite several attempts by her superiors to recall her to Vulcan. T'Pol's decision brought considerable scrutiny upon her from her superiors, and increasing support for her from her captain; she ultimately resigned from the High Command and accepted a field commission from Starfleet in 2154, resulting in her being granted the Starfleet rank of Commander.

Originally viewed by her crew mates with resentment and suspicion, T'Pol was forced to earn the trust of fellow officers, with Commander Charles "Trip" Tucker III being a particular focus of friction with her, due to his perception of her being a spy for the Vulcans and their very different personalities.

T'Pol is more emotional than many other Vulcans and has always struggled to control her emotions, something that greatly concerned her mother. Her emotions became even more difficult to control following an exposure to trellium ore, a toxic substance which damaged the part of her brain responsible for emotional control. Nonetheless, T'Pol serves as an icon of Vulcan integrity. Her willingness to question the decisions of her superiors, and her respect for Captain Archer position her at the fulcrum of human/Vulcan relations.

In Season 3, episode 24 "Zero Hour", while talking with Trip on February 14, 2154, T'Pol states that she "will only be 66 years old" on her next birthday. This places her birth in 2088 or 2089 (as measured on Earth), making her 62 or 63 years old at "Broken Bow". T'Pol was born the only child of T'Les, an instructor at the Vulcan Science Academy, and her (never named) husband. Per Vulcan tradition, T'Pol was bonded with a Vulcan named Koss while they were children and expected to marry as adults ("Breaking the Ice").

As a child, T'Pol's path in life was inspired by Ambassador V'Lar whom she watched negotiating with the Andorians during the Treaty of 2097 over possession of the planetoid Paan Mokar ("Fallen Hero").