Yes, a US attorney can practice in Canada. However, they must meet certain requirements and qualifications. US attorneys need to apply for admission to the specific Canadian province where they want to practice law. The requirements vary depending on the province, but generally, US attorneys need to pass the National Committee on Accreditation exams and complete additional courses or studies to bridge any gaps between US and Canadian legal education. Once admitted, US attorneys can practice Canadian law but are subject to the rules and regulations of the Canadian legal system. It is important for US attorneys to familiarize themselves with the specific provincial laws and legal requirements in order to effectively practice law in Canada.