Tara Maclay is a fictional character created for the action-horror/fantasy television series Buffy the Vampire Slayer (1997–2003). She was developed by Joss Whedon and portrayed by Amber Benson. Tara is a shy young woman with magical talents who falls in love with Willow Rosenberg, one of the core characters. Together, they help Buffy Summers, who has been given superhuman powers, to defeat evil forces in the fictional town of Sunnydale.

Willow was a popular character when Tara was introduced, and the onset of their relationship was met with some resistance from fans. Tara grows from a reserved girl who is unsure of herself to being the moral center of Buffy's circle of friends, named the Scooby Gang. Her relationship with Willow is consistently positive, and the first recurring depiction of a lesbian couple on prime time network series television in the United States. Tara is killed by a stray gunshot toward the end of the sixth season, causing Willow to go on a rampage. Series writers and producers received angry protests from some fans when Tara was killed. Whedon upheld that it was the necessary course to take to propel Willow's story arc further; both the show's producers and Amber Benson deny that there was any malicious intent behind the decision. Tara was included in AfterEllen.com's Top 50 Lesbian and Bisexual Characters, ranking at No. 15.

The book The Bewitching Hour by Ashley Poston is a Tara prequel novel that fleshes out her character more and explains how she ended up at UC Sunnydale.

Tara is introduced in the fourth season episode "Hush" as a college student who attends a Wicca meeting where Willow Rosenberg (Alyson Hannigan) goes to find some like-minded people. Tara is hesitant to speak out during the meeting and has a pronounced stammer that returns throughout the series when she is upset. She reacts positively during the meeting to Willow's suggestion that the Wiccan group discuss spellcasting, but the rest of the group scoff at the suggestion and silence Tara and Willow. Tara was created to appear in only a few episodes as a friend with whom Willow could learn magic and develop her skills. Amber Benson had known Hannigan previously but did not tell her she was up for the part. Benson almost missed a callback audition because she left town, but the casting department postponed the session so she could return and read. When she did, Hannigan found her on set and upon learning she was up for the role, told Whedon to hire Benson at the same moment Benson got the call from her agent that she had won the part. Benson and Hannigan had such chemistry that the relationship was written to be more intimate. In "Hush", Tara and Willow each individually attempt to use magic to move a heavy object, without success. They then join hands and easily fling the object across the room. Whedon and the producers found the scene to be very sensual. Network executives also noticed the chemistry between the actresses. After some discussion, Whedon informed Benson and Hannigan that the characters would become lovers.

Willow was featured from the beginning of the series and already had a strong fanbase. Earlier in the fourth season, she had a boyfriend named Oz (Seth Green), who abruptly left town. Oz returns in the episode "New Moon Rising", determined to win Willow back. That episode marked the first time Tara is introduced to the Scooby Gang as a whole, and Willow is faced with choosing between Tara and Oz. She favors Tara in the end, causing some of the show's fans to react angrily on the fansite message boards, with some leaving homophobic remarks and characterizing Benson as overweight and unattractive. Benson, who was referred to as "astoundingly non-Hollywood" by a Scottish journalist, frequented the boards and read the comments, finding them hurtful and taking some of them personally. She responded, protesting that she was, at 5 feet 4 inches (1.63 m) and 118 pounds (54 kg), quite slender, although she appears larger than her more petite costars. She went on to write:

You can judge me and Tara for being "fat", "gay", and "shy". I suppose that my being on TV gives you that right. But I DO NOT have to read what you say. I have enjoyed being a lurker. But my feelings just can't take the criticism. Those of you (you know who you are) with sensitivity will understand. Thank you for sticking up for us. Tara and I both appreciate it. I think that being a beautiful, heavy, lesbian witch rocks! No matters what happens, I'm glad I get the chance to walk in Tara's shoes.

Network executives encouraged the lesbian element in the relationship, but put strict guidelines on what could be shown. Buffy scholar Jeffrey L. Pasley summarizes the planning behind the relationship:

Whedon chose to sidestep the "statement" opportunity presented by Willow's turn to homosexuality, even as Buffy the Vampire Slayer was celebrated in the gay and lesbian community for providing the first committed same-sex relationship in the history of series television. Well aware that they were breaking new ground and being closely watched, the Buffy braintrust elected to depict the relationship honestly but unsensationally, avoiding the prurient ballyhoo that had accompanied fleeting homosexual encounters in other series like Ally McBeal and Party of Five. "It would start to get coy and, quite frankly, a little offensive, for two people that much in love to not have any physicality," Whedon explained [to The A.V. Club (5 Sept. 2001)]. "But the whole mission statement was, 'We'll put it where nobody expects it, and we'll never talk about it.'" Sex between Willow and her lover Tara was implied now and then from "New Moon Rising" on, and Willow's best friends Buffy and Xander were allowed to feel briefly uncomfortable with her switch in sexual preference (The Yoko Factor). Yet by design the relationship was treated matter-of-factly, with little comment made on its lesbian nature and little overt change in the characters' behavior. Love was love, whatever the partners' gender, and indeed for a long period from the end of season 4 to the middle of season 6, Willow and Tara were the Buffyverse's happiest and most stable couple.