He joins as the lottery operator attempts to halt a ticket sale slump and amid criticism over its distribution of money to good causes.
A cost-cutting drive is also in place, overseen by chief executive Dianne Thompson. This has led to 80 jobs being axed, including the most senior PR role, external relations director, last held by Sue Slipman, who left in October (PRWeek, 4 October).
A source close to the recruitment process said: 'There's no doubt Camelot has had a challenging time, not least in terms of its corporate profile.'
Gallagher, who joins in February in the newly created role of corporate affairs director, will take over the duties of head of corporate comms Andrew Jones, who is leaving next year.
But Gallagher will only have an advisory role over consumer PR, regulatory affairs and lobbying, all sections that previously reported to Slipman.
Consumer PR, headed by Jacquie Wilson, has been moved to the marketing team.
Government relations head Sarah Kennedy now reports to Thompson as does regulatory affairs director Colin Simms, who is set to retire next year.
Jones said his departure was his decision and was not a 'redundancy matter'.
At ITN Gallagher will be replaced by Sophie Jones, currently public affairs manager. Gallagher joined ITN in 1999.