The former St Mirren youngster left Celtic's training camp in Dubai nearly four weeks ago to hold talks over a move to the United States and has now officially put pen to paper on a deal with the Florida outfit.
The announcement on Inter Miami's website read: "Inter Miami CF announced today it has signed winger Lewis Morgan from prestigious Scottish Championship side Celtic Football Club for an undisclosed transfer fee."
The error was later altered to read "prestigious Scottish Premier League side Celtic".
Morgan, who joins for an undisclosed fee, will occupy one of the MLS new boys' international roster slots, and will be added to the full roster pending receipt of his International Transfer Certificate and P-1 Visa, the club has said.
Inter Miami Sporting Director Paul McDonough said: "Lewis is an exciting player that will contribute to our attack.
“He is a pacey and dynamic player who operates well in space. He has shown his quality in Scotland and in England and we’re happy to acquire him."
Morgan made 31 appearances for Celtic, scoring twice and laying on three more for his team-mates.
He could make his debut for Inter Miami in their first-ever MLS clash with LA Galaxy on March 14.