The manningtomiami.com site is advertised on a billboard along an Interstate near the Dolphins' complex. Under an image of Manning about to throw a pass in a Dolphins uniform, the sign reads "MANNING TO MIAMI.com."
The website encourages fans to fill out a form urging the Dolphins to bring Manning to Miami. A list of those supporting the campaign will be given to the Dolphins and Manning's advisers, the site says.
Manning has spent the past five months recovering from his third neck surgery in less than two years, and it's unclear whether he'll remain with the Indianapolis Colts.
At the NFL scouting combine Thursday, Colts general manager Ryan Grigson repeatedly spoke of the decision on Manning, who's due a $28 million bonus on March 8, as an ongoing process.
"Peyton has to be healthy, it has to be something that's spoken on, investigated and talked about," Grigson said. "But right now, like I said, it's a process that we're waiting for things to happen and doing the things that we have control of. Things that we don't have control of we just have no choice but to be patient and (perhaps) all you will be the same. ...
"I can't talk about Peyton's medical status right now."
Manning has broken all of Indianapolis' career records for quarterbacks and had never missed a start before last season. He's taken the Colts to the playoffs 11 times, captured seven AFC South titles in eight years, won two AFC championships, one Super Bowl title and a Super Bowl MVP Award.
Information from ESPN.com AFC South blogger Paul Kuharsky and The Associated Press was used in this report.