The 29-year-old opted out of his contract with the Miami Heat after a successful four-year spell with the club, and after a protracted saga James re-signed with his hometown club the Cavaliers.
Silver told reporters: "I really was moved by it. I thought it says a lot about who he is, who he's become over the last four years.
"I think his statement about northeast Ohio, about hard work, about this being about something larger than basketball and the NBA.
"I've gotten to know LeBron pretty well over the years, and so I think from that standpoint, I'm really more like a fan. This seemed to be a great moment for the league."
James won the NBA Championship twice during his time with the Heat.