Rawlinson is Slack's new chief people officer, effective at the end of September, the San Francisco company said.
"Today we have a unique opportunity to reimagine how we manage, how we lead and how we organize," Slack Co-Founder and Chief Executive Stewart Butterfield said in a statement.
"Nadia will play a key role in that, both for Slack and for our customers."
"Since the pandemic started our people team has done a remarkable job in maintaining and even strengthening that culture in the face of many wholly new challenges," he added.
Rawlinson will succeed Robby Kwok, who has been named chief of staff to Butterfield.
"During these uncertain times, supporting Slack’s employees and prioritizing a strong, inclusive culture is more important than ever," Rawlinson said.
"I believe the company is at a unique inflection point: Slack is emerging as the de facto remote headquarters for millions of knowledge workers around the world."
In this role Rawlinson oversaw global HR strategy and development for Live Nation’s 35,000 employees. At July 31 Slack had 2,431 employees.
For the quarter ended July 31 Slack reported a net loss of 13 cents a share against a loss of 98 cents in the year-ago quarter.
Revenue rose 49% to $215.9 million from $145 million.
The popular messaging tool has seen use of its messaging and other functions surge during the pandemic.
At last check shares of Slack were down 1.3% to $25.31.