Generations of the Kingsmill family have owned and operated the business in downtown London, Ont., in what was once the city's main shopping area.
Tim Kingsmill, who started working at the store as a teen and has been president since 2003, is planning his retirement after 35 years in the retail business.
He says the decision to sell one of the few remaining independent, family-owned and operated department stores in Canada has been "tremendously difficult."
Details of the sales process weren't announced but the store will operate as usual in the meantime.
"This type of transition must be carefully planned," Kingsmill said in a statement.
"The store continues to be successful, and as such, the time is now right for me to begin planning this next step."
Kingsmill's sells a variety of goods, including home furnishings, fine china and collectibles, women's, men's and children's fashions, cosmetics, linens, gifts, kitchen ware and luggage.
Although it has been repeatedly updated, the store continues to have features from a by-gone era such as a manually operated elevator and pneumatic tubes that whiz paperwork around the building.
The store has burned down and been rebuilt twice during its 148-year history.
The current building, built in 1932, is spread over five floors and features the original tin-plated ceilings and hardwood floors.
The store was opened as a dry goods store in 1865 by Thomas Frazer Kingsmill, an Irish immigrant — the first of five generations to operate the business.
"Tim has been an incredible leader," said Fred Kingsmill, board chair of Kingsmill's and Tim's father. "He has ensured the store's continued success while respecting the values of quality and service that have always been so important to our family. I am tremendously proud of him and wish him nothing but the best as he begins to map out the next stage of his life."