The 27-year-old was signed for Southampton by current Everton boss Ronald Koeman but was restricted to just 24 Premier League appearances during a three-year stay on the south coast.
Martina became a free agent this summer after his deal with Southampton expired and Koeman has secured a reunion with the full-back.
Martina told Everton’s official website: “Everton is a big club with big ambitions and I'm really looking forward to joining this group of players and the manager as we try to step forward next season.
“Obviously, I know the manager from my time at Southampton, so I know what he wants and he knows what I can do.
“Everton supporters are really passionate about their club and everyone's excited about where the club is aiming. You can see this is a club that wants to achieve something and the players we are bringing certainly show this.
“When you come to a new club, you need to get to know one another so the training camp in Holland will be great for me and for the other new players as well. We will play against Twente, one of my old clubs, too, and I'm really looking forward to showing everyone what I can do.”