
Brush replaces Martin MacConnol, chief executive of Wardour, who had been in the position since 2008.
The APA became independent from the Periodical Publishers’ Association in January this year, although it continues to be an affiliated member of the PPA.
Brush founded Axon, whose clients include M&S, with Paul Keers in 1994. Before that she worked at Redwood.
Julia Hutchison, the APA’s chief operating officer said: "We’re looking forward to getting Ellen on board as the new chairwoman. Her experience in the industry speaks for itself and I am extremely confident that she will pick up where Martin left off, helping propel APA into its next phase of growth."