Canada cannot deliver on its international obligations under the Paris Agreement without meaningfully engaging its small business sector. Small businesses are more than simple profit-maximizers: they are social and political actors. Policies and incentives to foster sustainability should be carefully tailored to respond to the variety of drivers at each size of firm, rather than employing the same approach across the spectrum. Government can accelerate small business sustainability innovation by providing information, cases and success stories; technical skills and expertise; financial support and incentives; and legitimation.