Activists took to the streets and rallied at airports in major cities to protest the order, which many viewed as discriminatory and unconstitutional. Politicians on both sides of the aisle joined the opposition.
CNBC's Andrew Ross Sorkin said Monday that some CEOs he had spoken to were avoiding speaking out against the ban because they are "scared out of their minds about being attacked [by Trump] ... and what that's going to do for their business."
But many execs are speaking out.
Google co-founder Sergey Brin, who came to the US as a child to escape religious persecution, was spotted at a protest at San Francisco International Airport on Saturday.
"I'm here because I'm a refugee," he told Forbes.
Tech executives have been the most outspoken against the ban so far. But by Monday, other corporate leaders in finance and health care had joined in opposition, issuing statements to employees and customers expressing concern.
- Portia Crowe, Alex Heath, Lydia Ramsey, and Cadie Thompson contributed reporting.