Madison "Maddie" Russell is one of the two main human protagonists (alongside Mark Russell) of the 2019 film, Godzilla: King of the Monsters, and one of the two deuteragonists (alongside Jia) of the 2021 film Godzilla vs. Kong.
She is the daughter of Mark Russell and Emma Williams who has grown up traveling the world with her mother on field assignments following the death of her brother Andrew during Godzilla's battle with the MUTOs in 2014. To start off with, she was living in Monarch Outpost 61 in China's Yunnan Province, where her mother was studying the Titan known as Mothra. Madison maintained a distant relationship with Mark, who resigned from Monarch and separated from Emma in 2014, though she contacted him several times a week. In 2019, she witnessed Mothra's emergence from her egg up-close, only to be abducted by the eco-terrorist Alan Jonah along with Emma. After Emma and Jonah's plan to awaken the Titans around the world resulted in Ghidorah using them as his servants to devastate the world's ecosystems, Madison stole her mother's sonar device, the ORCA. Using Fenway Park's speakers, she managed to halt most of the Titans' rampages, while summoning Godzilla and Mothra to Boston for a final confrontation with Ghidorah and Rodan. In 2024, Madison believes there is a reason for Godzilla's erratic behavior, suspecting a conspiracy formulated by the organization, Apex Cybernetics and proceeds to investigate with assistance from her friend Josh Valentine and former Apex Cybernetics technician Bernie Hayes.