Milroy, who has more than 15 years of PR experience, will join Eloqui to develop the agency's crisis and issues practice, according to MD and former colleague Chris Genasi.
Before co-heading Weber Shandwick's crisis team, where she has been for the last six months, Milroy was a director in the agency's corporate practice.
She has worked on crisis and issues management with clients such as Unilever, Royal & Sun Alliance and Woolworths.
Eloqui, which was set up in February by Genasi, the former global director of strategy at WS, and ex-Shandwick International CEO Richard Sermon, also specialises in public affairs. Genasi said he intends the agency to be ten-strong by the end of the year.