Markovic becomes Liverpool's fourth signing of the summer.
Liverpool have completed the signing of Lazar Markovic from Benfica for a fee believed to have been around £20 million.
The 20-year-old winger signed a long-term deal, and becomes the Reds fourth signing of the summer, following Rickie Lambert and Adam Lallana from Southampton, along with Emre Can from Bayer Leverkusen.
He is likely to provide competition for the likes of Raheem Sterling, Philippe Coutinho, and possibly youngster Jordon Ibe along with Lallana.
Markovic has been highly rated by those in the Serbian national set-up, and former Chelsea manager Avram Grant hailed him as 'one of the best talents I've ever seen at 19 years of age'.
The winger came through the youth ranks at Partizan Belgrade before making his debut for the senior side towards the end of the 2010/11 season. He played for two further seasons at the club, winning the Serbian league title in each season before moving to Benfica in 2013.
He won the Portuguese treble during his time at Estadio da Luz, as well as helping the side reach the Europa League final in Turin, but was sent off in the semi-final against Juventus for a touchline brawl with Juve's Mirko Vučinić.
On joining the club, Markovic told the club's official website: "I am very happy that I have joined such a great club. I hope that I will fulfil the expectations of the supporters, coaches, players and all connected to the club.
"I went to Partizan and won the title. I went to Benfica and won the title. Now I have joined Liverpool and want to win the title, 100 per cent."