These titans of industry not only view the order as discriminatory, but also detrimental to economic and technological growth.
"Apple would not exist without immigration, let alone thrive and innovate the way we do," Apple CEO Tim Cook wrote in an email to staff. "I've heard from many of you who are deeply concerned about the executive order issued yesterday restricting immigration from seven Muslim-majority countries. I share your concerns. It is not a policy we support ... In the words of Dr. Martin Luther King, 'We may have all come on different ships, but we are in the same boat now.'"
He added, "There are employees at Apple who are directly affected by yesterday's immigration order. Our HR, Legal and Security teams are in contact with them, and Apple will do everything we can to support them. We have reached out to the White House to explain the negative effect on our coworkers and our company."
Facebook CEO Mark Zuckerberg wrote on his Facebook page on Friday, "I'm concerned about the impact of the recent executive orders signed by President Trump. We need to keep this country safe, but we should do that by focusing on people who actually pose a threat. Expanding the focus of law enforcement beyond people who are real threats would make all Americans less safe by diverting resources, while millions of undocumented folks who don't pose a threat will live in fear of deportation."
Like Apple's Cook, Google CEO Sundar Pichai addressed the impact of the order on his employees.
Kalanick, the CEO of ride-sharing service Uber, said the ban goes against American values.
"Allowing people from all around the world to come here and make America their home has largely been the U.S.'s policy since its founding," Kalanick wrote in an email to staff that he shared on his Facebook page. "That means this ban will impact many innocent people—an issue that I will raise this coming Friday when I go to Washington for President Trump’s first business advisory group meeting.
Kalanick said Sunday evening that his company would help drivers who are affected by the order by providing legal support and compensation for lost earnings.
The founders of Lyft, Uber's top competitor, said in statement, “Banning people of a particular faith or creed, race or identity, sexuality or ethnicity, from entering the U.S. is antithetical to both Lyft's and our nation's core values. We stand firmly against these actions, and will not be silent on issues that threaten the values of our community."
“We know this directly impacts many of our community members, their families, and friends. We stand with you, and are donating $1,000,000 over the next four years to the ACLU to defend our constitution,” they said.
Microsoft's Indian-born CEO, Satya Nadella, addressed his own background in a LinkedIn post.
"As an immigrant and as a CEO, I’ve both experienced and seen the positive impact that immigration has on our company, for the country, and for the world," he wrote. "We will continue to advocate on this important topic."
AARON LEVIE, BOX
Levie, CEO of the Palo Alto, California, enterprise cloud company Box, tweeted, "On every level -moral, humanitarian, economic, logical, etc.- this ban is wrong and is completely antithetical to the principles of America."
DREW HOUSTON, DROPBOX
"Executive orders affecting world's most vulnerable are un-American," tweeted Drew Houston, CEO of Dropbox, a file sharing service based in San Francisco. "Dropbox embraces people from all countries and faiths."
JEFF IMMELT, GE
General Electric CEO Jeff Immelt said in an internal company blog that he was concerned about the order, noting that GE has "many employees from the named countries," and "these employees and customers are critical to our success and they are our friends and partners."
Of those directly affected, he said: "We stand with them and will work with the U.S. administration to strive to find the balance between the need for security and the movement of law abiding people."
ABC News' Zunaira Zaki contributed to this report.