Mary Gibbs gives Boo in Monsters, Inc. the spontaneous, unpolished voice of a real child. Her screen work offers little basis for sweeping claims, but this performance earns our affection without asking for it.
Fi1m perspective
Boo's babbling in Monsters, Inc. (2001) sounds unconcerned with the plot. Mary Gibbs was a toddler when the recordings were made, and much of what we hear came from following her around the studio with a microphone. She was playing, with little interest in standing still to deliver lines. We rate the result highly, while being wary of attributing an adult actor's calculation to it. The pleasure lies in hearing a child whom the film has not tidied up too much.
John Goodman's gentler delivery as Sullivan gives those small sounds the attention they need. His scenes with Boo have room for care even when the surrounding film is busy rushing about. We were unexpectedly moved by their relationship, because Goodman makes Sullivan's attention to her feel patient and particular. Director Pete Docter allows that affection to develop without turning every exchange into a lesson. Boo can matter without having to explain what anyone ought to learn from her, and Gibbs's unforced voice helps make that possible.
The career beyond that performance has been sparse, which limits what we can reasonably say about Gibbs's development as an actor. Archive recordings were reused in Inside Out (2015), extending the life of the material without constituting a new performance. Her return as Janessa Jensen in the audio drama Heroes of Extinction (2022) marks new voice work after a long gap. That is a separate performance to assess; Boo alone cannot tell us what sort of actor the adult Gibbs has become.
The risk with such young voice work is that charm gets asked to do everything. Here Goodman and Docter give it the support it needs, allowing Boo to be funny and affecting without insisting that every sound deserves our approval. Some supporting characters in Monsters, Inc. could use more attention, but that reservation does not weaken our warmth towards Boo. Start there, particularly if polished, precocious screen children usually test your patience.
Biography
Mary Gibbs is an American voice actress. She was born on 5 October 1996 in Pasadena, California. She is best known for voicing the toddler Boo in the Pixar film Monsters, Inc. (2001).
Her father, Rob Gibbs, was a Pixar story artist and director who worked on Toy Story 2 (1999) and other films. As a toddler, Gibbs recorded her lines for Boo while moving around the studio, with her parents assisting the crew. Archive recordings of her performance were later reused in Inside Out (2015) for baby Riley and in Monsters University (2013).
Gibbs has also voiced Baby Kiara in The Lion King II: Simba's Pride (1998) and Sha-Ron in Mulan II (2004). She maintains a YouTube channel, Boo Grown Up, and returned to voice acting in the audio drama series Heroes of Extinction (2022–2023).
