He replaces former Dolphins president Mike Dee, who essentially swapped jobs and recently took over Garfinkel's old role in San Diego.
"As [Dolphins owner] Steve [Ross] said, sometimes things in life happen for a reason, and it just happened to be that was the case this time," Garfinkel said.
Garfinkel said he and Dee have "crossed paths over the years."
"We have a lot of mutual friends. I know him a little bit. I don't know him well. I did reach out to him when he got the job there. I congratulated him. He sent me a note back, and I'm sure at some point we will talk," he said.
Garfinkel worked as the chief executive officer for the Padres from 2009-13. Before that, he was executive vice president and chief operating officer of the Arizona Diamondbacks. He spent five years with Chip Ganassi Racing Teams as executive vice president. He has no NFL experience.
The Dolphins are maintaining their same internal structure. Therefore, Garfinkel will be in charge of the business end of the organization only and will have no say in personnel matters. General manager Jeff Ireland and coach Joe Philbin will continue to run the football side and answer directly to Ross.