B.C.'s Health Minister Terry Lake said Mackenzie has been working for seniors for 20 years. Most recently she has been the executive director of Beacon Community Services in Victoria.
She has also worked in the provincial public service and published papers on the retirement industry.
The seniors' advocate position is the first of its kind in Canada. Like B.C.'s representative for children and youth, Mackenzie will be expected to investigate allegations of abuse and keep an eye on the government care system.
B.C. Premier Christy Clark first mooted creating the post last year after a 2011 investigation by B.C.'s ombudsperson uncovered a wide range of problems with the system and made 176 recommendations.
Clark then promised to appoint the first advocate in February, 2013.