Matthew Harding is one of Adelle DeWitt's superiors in the Dollhouse organization.
In "Belonging", Adelle informs Harding that Nolan Kinnard not only falsified the reasons Priya Tsetsang was recruited to be an active, but demands that Sierra be given to him permanently. Harding is indifferent to her objections, and orders her to give Kinnard what he wants, even threatening her with "termination." He also mentions he knows of her off-hours experience as "Miss Lonelyhearts".
Harding took over the L.A. Dollhouse from Adelle DeWitt for about three months, greatly expanding the R&D department, led by Topher Brink. He gave it back to DeWitt after she delivered Topher's remote imprinting technology to him.(S2: "Meet Jane Doe")
In 2020, Harding was a high-ranking executive at Neuropolis. He gave orders to former Rossum executive Clive Ambrose, and both used new bodies. Ambrose objected to Harding "wasting" bodies by eating too much, getting them obese and then "acquiring" new ones. Ambrose brought Harding a new set of dumbshow bodies, among whom pretending to be one was Paul Ballard. Harding recognized Ballard and ran away, leaving Ballard to assault Ambrose.
Later on, the resistance restored all personalities to their previous selves, thus erasing Harding from his host body or bodies. (S2: "Epitaph Two: Return")