MacLean joins from Radian Housing Association – a 21,000 house provider based in the south-east of England.
She replaces Mike Crozier who has been Weslo’s operations director for the past 24 years after forming the company with three colleagues to take over Scottish Homes’ houses in West Lothian in the first staff led transfer of its kind.
MacLean has also worked at New Forest District Council, Home Group and Scottish Borders Housing Association.
She said: “I am delighted to be returning home to live in Scotland after many years in the English housing sector.”
Crozier said: “After 24 years I can look back with pride and satisfaction at having been part of an organisation that has grown from 25 to 83 staff who have all contributed to making our tenants’ lives better.
“I wish Diana every success in her new job and I’m sure she will ensure that the company goes from strength to strength.”
Weslo’s chief executive Mike Bruce added: “I’m very pleased that we’ve managed to attract someone of Diana’s calibre to come and work with us and I look forward to utilising her wide experience in continuing to provide excellent services for our tenants.
“I’m very sorry to lose Mike of course but after 24 years he moves into a well-deserved retirement with our best wishes.”