Paul Eastham, the former deputy political editor of the Daily Mail and most recently head of media for Ofsted, has joined the charity as interim head of media for three months.
The organisation is still hunting for a permanent replacement for Richard Johnson, who left in August.
Meanwhile, the charity's senior publicist Nicholas Breakspeare is leaving the charity on 10 October to head up UK comms for DLA Piper. He will report to the head of media relations and PR Helen Obi.
Nick Bell, who held the role previously, will look after internal comms instead.
Press manager Samantha Shaw is also leaving the Children's Society after nearly eight years, to be head of media and comms at the Marine Society and Sea Cadets.