Peter Campbell joined as town planner from Deloitte; Lauren Thompson joined as senior planner from Cheshire East Council; Diane Ellis as associate planner from Consilium Planning; and Lindsay Whitley from IBI Group as principal urban designer.
Elsewhere in the North West, Peter Shannon joined the Cumbria office from Allerdale Council as a senior planner.
WYG said the appointments were in response to an increase in new business after its acquisition of London-based Alliance Planning in September. There are now 12 fee earners in the firm's Manchester planning team.
Paul Shuker, director, said: "It has been an exciting time for the team as our overall business has gone from strength to strength over the last 12 months. We continue to deliver innovative and complex projects for our clients and partners across a diverse range of sectors, and I am delighted to announce these appointments in order to allow us to meet current and future clients' needs moving forward."