The exec was only promoted to general manager of the channels last year, and will now take the helm at the pair.
Before that promotion McCarthy was general manager of MTV’s digital nets.
In his new role he will continue to report to Doug Herzog, president of the Viacom Music & Entertainment Group.
Herzog said: “Within a remarkably short time, Chris has driven record growth across all screens and done an incredible job of reinventing the VH1 brand, bringing the focus back to its rich pop culture heritage.”
McCarthy is credited with overseeing a successful ratings revamp of the MTV2 and Logo channels in the US, and more recently reinvigorating VH1 and Logo.