"The use of Teams at the corporate enterprise level is really taking off," the "Shark Tank" investor said on CNBC's "Squawk Alley."
"I think that's one of the reasons Microsoft's stock is doing so well."
Shares of Microsoft rose 3% to $177 each on Thursday. While the stock sits about 7% below its February high, it is up 12.2% year to date. The S&P 500, by contrast, is down about 13% in 2020.
Teams, which lets people exchange chat messages and hold video calls, is part of the Office 365 subscriptions that also includes access to Word and Excel.
Herjavec, founder and CEO of cybersecurity firm Herjavec Group, said his company has recently turned to Teams as work-from-home policies in response to the coronavirus pandemic changed how business is conducted.
"When all of this first happened we wanted to use Zoom because all our customers use Zoom but I've got to tell you, some of the security issues are really pretty bad within Zoom," he said.
Zoom has seen dramatic usage increases as the Covid-19 outbreak forced millions of people to stay at home.
While initially targeted toward enterprise use, the company's service has been adopted by schools and people who want to host virtual happy hours with friends, for example.
Herjavec told CNBC earlier this month that in general his company, which provides cybersecurity products and services to business, has seen a spike in security breaches. He said the pandemic has created "the golden age for hackers."
The increased use of these services will likely outlast the coronavirus crisis, Herjavec argued.
"Customer meetings will change forever. In the past, I never thought that I could do a Zoom call or a Teams call with the CEO of a company I'm trying to sell to," he said. "In the future, I don't think my customers will want me to come and see them."
Also on Thursday, Microsoft announced a deal with the National Basketball Association to use its Azure cloud and Surface tablets.
Disclosure: CNBC owns the exclusive off-network cable rights to "Shark Tank," on which Robert Herjavec is a co-host.