Marcy Lannan is a Canadian voice actress based in Calgary, Alberta, who has worked extensively with Blue Water Studios. She is also a stage performer and a member of the Spectacle Blue Studios theatre company.

Lannan pursued formal training in the dramatic arts, graduating from the University of Calgary's Fine Arts program with a major in Drama in 2005. Shortly after completing her university education, she auditioned for an English dub of an anime series. That audition led to her being cast in her first major voice role. Outside of her work in voiceover and theatre, Lannan also works as a performance coach for aspiring actors and is a trained aerialist and trapeze artist.

Lannan is perhaps best known for her roles in the interconnected anime series My-HiME and My-Otome. In My-HiME, she provided the English voice for Nao Yuuki, a complex character with a mysterious and dark past. The actress has stated that she enjoyed playing a character with a darker side and found the experience of gradually learning about Nao's backstory to be particularly rich and emotionally engaging for her performance. She reprised a version of this character in the follow-up series My-Otome, voicing Juliet Nao Zhang. Lannan noted in an interview that she observed the shift in the character between series, finding it interesting to play the change while still trying to retain a hint of Nao's original personality.

Beyond these signature roles, Lannan's anime voice acting credits include Machi in the 1999 series of Hunter x Hunter, Tomoe Maejima in Full Moon o Sagashite, Chiaki Yabe in Futari wa Pretty Cure, and a co-worker in Strawberry Marshmallow. She also voiced the character Juliet Nao Zhang in the OVA sequel My-Otome Zwei. In her work on My-HiME, in addition to playing Nao Yuuki, she occasionally provided the voices for incidental characters and background voices for large group scenes.