Jay's Moving has 11 full-service terminals and warehouses and a fleet of over 600 trucks and trailers.
Mullen Group says Jay's will be operated as a stand-alone business within the group.
Dennis Doehl, the current owner of Jay's, has agreed to remain for the rest of the year to help with the transition.
"We are extremely pleased to add Jay's to our organization," said Murray K Mullen, chairman and CEO of the Mullen Group.
"This is a great company with an established history and a strong management team. As such, we anticipate a quick and smooth transition."
Mullen didn't disclose financial terms of the purchase but said it expects Jay's to add between $35 million and $40 million of annual revenue, with operating margins in line with other businesses within its trucking and logistics segment.
It said the purchase will be funded from Mullen's existing cash reserves.
Mullen Group is a large provider of specialized transportation and related services to the oil and natural gas industry in western Canada and as one of the country's leading suppliers of trucking and logistics services.