Lucy Heartfilia (ルーシィ・ハートフィリアRūshi Hatofiria?) is the main female character of the series. She joins Fairy Tail at the start of the series, having always wanted to be a member. She is always teamed with Natsu when on a job, though the frequent battles they get involved in have left her wishing she could do an easy job by herself. Lucy is one of the saner and more stable members of Fairy Tail, often being the only one to recognize the absurdity of her teammate's actions. She is also very confident in her appearance and sex appeal, exuding a certain amount of vanity. Lucy comes from a wealthy family, her father owning a large valley that serves as his estate's garden. Because she is estranged from her father, she left him and his fortune after the death of her mother so that she could follow her own path. In the series, it is revealed that father once told Lucy that he and her mother came from the guild Love & Lucky, and the "K" in "Lucky" fell off so the sign read "Love & Luc y"; the memory resonated strongly with them, thus they decided to name their daughter Lucy. She is voiced by Aya Hirano in Japanese and Cherami Leigh in English. Her given name was inspired from The Beatles song "Lucy in the Sky with Diamonds".
Lucy practices Celestial Spirit magic, a skill that allows her to summon spirits from another world using Gatekeys. Before she is allowed to use the key she must sign a contract with the spirit to decide upon when she is allowed to summon them. There are two types of keys: silver keys, which are common and of a large variety, and twelve extremely rare gold keys that open the "Twelve Gates of the Zodiac." Her Celestial Spirits have varying levels of power, with different ones suited for different tasks. For example, Aquarius can control water, while Taurus has enormous strength. She can summon multiple spirits (an uncommon ability) at once for short periods of time, but tires out easily when doing so. Lucy's main weakness is she cannot perform magic without her keys, although Loke is able to appear with or without being called out. Along with her keys, she also carries a whip which she is proficient with.