As assistant chief executive of comms at the borough, she leads a team of around 40 and is one of the capital's most senior council PROs.
A Camden spokeswoman said the council intended to find a permanent replacement but a final decision will not be taken until CEO Steve Bundred returns from annual leave next month. An interim replacement has not yet been appointed.
Colledge, who described her imminent departure as 'an amicable parting', said her decision to leave was taken following the death of a friend, at a time when her children are starting new schools and after achieving targets of creating a more strategic PR focus and winning the Local Government Chronicle's Council of the Year award.
She added that she had made no firm plans for the future but is likely to remain in PR.
Before joining Camden three years ago, Colledge was head of communications for the Royal Borough of Kingston.