Tuilagi has played for Leicester Tigers and Leeds Carnegie, as well as a stint of Rugby League at St Helens before choosing Union as his code of choice.
"Andy is exactly what we want in our back line," said Dragons Head Coach Darren Edwards. "We were keen to look at the strengths we have within our squad and make careful signings based on players who we feel will add to our game. Having worked with Andy at Leeds, I'm very aware of his qualities as a player and am confident that he will be successful at Rodney Parade.
"We have a great deal of skill and pace in our backs and Andy will bring a physicality and a line-breaking ability that will really compliment our current squad."
The Samoan's potential signing at the Dragons has been the cause of media speculation for several months, but regional Director of Rugby Rob Beale confirmed the signing this week which had been delayed by red tape.
"This has been a very long process for the Dragons and for Andy," he said. "I know there has been media speculation over the past couple of months, but we had to ensure that this deal was done properly and that Andy had the necessary documentation in place before the signing was made.
"Having said that, Andy's reputation speaks for itself and I am confident that the wait will be well worth it."
Media will have the opportunity to interview Tuilagi at the region's press conference today, 2pm, Bisley Stand, Rodney Parade
63x46.png){kind=logo}