Sabrina Duncan was portrayed by Kate Jackson in the first three seasons of the show (1976-1979). A beautiful woman, the shorter haired brunette, Sabrina is known by fans as the "Smart Angel". Nicknamed "Brie" by her co-workers, has a slight Alabama accent and is the most feisty of the three original Angels, as well as possessing the most unique sense of humor. Sabrina is the "unofficial leader" of the Angels. She is the pragmatic and analytical member of the trio, speaks five languages, is considered an intellectual and approaches danger with the calm of the eye of a hurricane. She serves as a calculating professional. Sabrina  was a more strategic thinker than the other Angels and acted informally as the brains of the operation. However, Charlie and Bosley still helped connect the dots. She was sensible, no nonsense, rough and brave. Sabrina was not only intelligent, she was strong and assertive and able to take charge of every  investigation (which she always did). She had the dual role of being the "smart one and team leader" of the group and she carried it off with believability. Sabrina tended to take "outside" covers, such as a reporter, photographer or employee. Meanwhile, the other Angels would approach a case from the "inside", such as appearing as a bikini model, circus clown, or spa guest.

	Sabrina was the one who kept out of the way and oversaw things from a distance, reporting regularly back to Charlie. Typically, Bri would pull the pieces together toward the end of each episode, act as backup in the van, and eventually assist in rescuing the Angel in danger. However, she was often the Angel in mortal peril as well. In the Agency conferences, she was the most assertive in dealing with Charlie.

Sabrina's beauty and brains meant she had been both a cheerleader and a brilliant student at school. Her character is arguably the best and most "realistic" Angel to have graced the series. Among the brunette's other attributes is her ability to speak fluent Spanish, French and other languages. Sabrina lives in a security building on the top floor. Her ex-husband's name is Bill Duncan, who happens to be on the police force. Her father, lives on the beach. It is revealed that Sabrina majored in Political Science when she was in college.

Past: She was born Sabrina Blaylock. Sabrina's father was a General in the Army. Before joining the Townsend Agency, Sabrina was an LAPD officer. She is the only Angel to have been married (her ex-husband, Bill Duncan, appears in two episodes)

Fashion: Sabrina Duncan didn't have the sex appeal the other Angels did. She didn't have the hair or the sex kitten style. She is very pretty but not in a frivolous way. Her fashion signature includes turtlenecks, scarves, bell-bottomed blue jeans and tight work shirts and is the only Angel who never appears in a swimsuit on the show. Sabrina favored sensible turtlenecks over bombshell bikinis. Naturally, she was just as stunning as her fellow detectives.

But she was just more comfortable wearing casual clothes and working behind the scenes. She is usually seen wearing three-piece suits of blazers, vests pants or skirts. She tends to be seen behind the bar at the Townsend Agency Office. This is in part because of Kate Jackson's disinterest in the glamour aspect of the show.

Romance: When Charlie’s Angels first began, Sabrina was the only Angel with a regular boyfriend (her ex-husband, police detective Bill Duncan). The angle was dropped in the second season, enabling the series to do episodes such as “Angel in Love”, in which the normally unflappable leader of the Angels fall head over heels for a man who may be the leading suspect in a murder investigation. Like all the Angels, Sabrina romanced many men while on the job, like Dean Martin (Frank Howell) in "Angels in Vegas",  Edward Power (Jim Taylor) in "The Mexican Connection", Hugh O'Brian (Tony Mann), the owner of "Feeline" magazine in "Lady Killer", James Darren (David Barzak) in "Circus of Terror" and more. These never lasted beyond a specific episode or ended badly with the man being the villain.

	Car: Sabrina Duncan drives an orange Ford Pinto with license plate number CALIFORNIA 127-UBO. She is an excellent driver and she even took place in a car race as we see in the episode "Hellride".

Covers and Techniques: Sabrina's brain and clever way of thinking is her top advantage. She is the "unofficial leader" of the trio, a female Sherlock Holms. It is not surprising that Sabrina is outstanding at playing chess. Sabrina is also an excellent car driver and a sharp gun shooter, she loves horse back riding and is a professional skier. She also proves to be a sharp football player and is a master in disguises. Some of her covers included a fashion designer, a photo stylist, a flight attendant, a race car driver, a nurse, a secretary, a reporter, a clown, a prostitute, a football player, a lady jockey, a cheerleader coach, a skier, an art teacher, an Irish maid and more.

	Why did she leave: Comparatively more straitlaced than her colleagues, Sabrina Duncan eventually left the Agency after three years of dedicated service to remarry and raise a white picket-fence family. Unlike Jill, Sabrina never comes back. In the season 4 opener, we learn that she will be having a child.