Byrne oversees the newly merged firm's corporate comms, including media relations, PA and CSR. She will begin her London-based job with a comprehensive review of comms strategy.
Boots' merger with Alliance Unichem was completed last month.
Boots director of comms Jayne Mayled is leaving at the end of this month (PRWeek, 4 August).
Alliance Unichem's communicator - director of corporate comms for UK and Europe Yves Romestan - has been confirmed in the role of director of central marketing and comms for Alliance Boots Wholesale and Commercial Affairs.
Byrne joined Egg in 2001 but was made redundant earlier this year. She spent five years at Weber Shandwick, and is the ex-wife of its CEO Colin Byrne.
Alliance Boots head of financial media relations Donal McCabe said agency arrangements were yet to be finalised, with Finsbury (formerly Boots' financial adviser), Gavin Anderson and GCI UK (both UniChem) all still retained.
