O'Connor will be the president of business operations.
O'Connor is the second woman to serve as president of a Major League Baseball team, after Catie Griggs of the SeattleMariners, but the Marlins are the first major U.S. sports franchise to have women as both president and general manager.
The first woman to hold the position in one of the four major sports leagues was hired by Miami in 2020.
"When I talk to young girls, I like them to see me in my role because I didn't feel like I had that role model," O'Connor said. I want people to know that it's possible when they see me.
O'Connor has been with the Marlins for two years.
She is expected to be in charge of sales and marketing.
"Her leadership will continue to guide the Marlins organization towards our goal of sustained success while strategizing additional new ventures to grow our business and enhance our brand recognition," Sherman said.
✨ Watch more top videos, highlights, and B/R original contentO'Connor took over as the organization's CEO in February.
A team coming off back-to- back losing seasons will look to O'Connor and Ng.