The account was previously held by Custard Communications.
Hills Balfour will develop a campaign to raise awareness of Alton Towers Resort as a conference, corporate events and team-building venue, targeting conference agents, direct bookers and group organisers.
The account will be led by Jo Hartley, senior PR director at Hills Balfour.
Rachael Cotton, head of trade and corporate sales at Alton Towers Resort, said: "We are delighted to be working with Hills Balfour to raise awareness of the Alton Towers Resort brand among key decision-makers in the corporate meetings, events and incentives industry. We look forward to raising our profile as a leading UK events venue."