The 24-year-old midfielder returns to the States after an unsuccessful spell with Premier League side Stoke City in which he made just four appearances for the Staffordshire club.
Shea had stints on loan at Barnsley and most recently at Birmingham City during his time in England yet, despite his failure to make an impression across the Atlantic, head coach Adrian Heath is delighted to have added the former FC Dallas man to the squad.
"I can't speak enough about the talent and passion that Brek brings to the squad," Heath told Orlando's official website.
"Having had a chance to watch him train with us over the summer, I was impressed with the calibre of player he is and with his desire to win.
"I think those qualities fit well with our style of play, our team's philosophy and the other talented players on our squad.
"We have a lot work to do to prepare for the start of the season but we have a talented roster with which to start."
Orlando were confirmed as an MLS franchise in November 2013 and will make their debut in the 2015 campaign.
Shea has 27 caps for the USA, scoring two goals.