McAndrew joins Cicero on 14 September following 25 years in broadcast media.
Before her current nine-year stint at Sky News – which included leading the channel's royal wedding coverage in 2011 – she held a number of roles at the BBC, including as assistant editor of Newsnight, as well as working for The World at One and PM with Eddie Mair.
Mike Robb, executive director at Cicero, said: "Broadcast is still an area many organisations fear, yet we do not believe this needs to be the case. Kate adds significant experience to the Cicero team and ensures we are able to support our clients in generating the cut-through they deserve in broadcast."
McAndrew will join Cicero in new offices in the City of London, which the agency moved into yesterday.