The deal, first announced in June, was completed via a scheme of arrangement.
"The completion of the Patersons transaction marks the beginning of a new chapter for our Australian business, as we systematically expand our presence with a leading wealth management business in Australia," Canaccord Genuity Australia CEO Marcus Freeman said.
"Together we will be a stronger market participant with an expanded national presence in the Australian financial services industry, offering an expanded suite of resources, products and services for our combined clients in wealth management and capital markets."
Patersons will now be known as Canaccord Genuity Patersons.
The wealth management business of Patersons has more than 100 investment advisors and around A$3 billion on its investment management platform and roughly $12 billion in client trading and advice-based accounts.
It is understood there have already been job losses as part of the integration process.
The combined group will have more than 280 employees across 10 Australian offices.
"We entered this arrangement with a strong commitment to preserving our long-standing heritage of operating in the best interests of our clients and building on the cultural alignment between our two firms," Patersons executive chairman Michael Manford said.
Patersons earned net revenue of $58 million and operated on a breakeven basis after adjusting for exceptional and deal-related costs in the 2019 financial year.