Sansone was born in Munich in Germany and his first club was SV Neuperlach. At the age of 10, he transferred to Bayern Munich, where he progressed through the Junior Team. He made his debut for Bayern's reserve team in January 2010, in a 3. Liga match against Dynamo Dresden. He made three more appearances in the 2009–10 season, and was a regular in the team during the 2010–11 season. In October 2010, he was named on the substitutes bench for the first-team in a Bundesliga match against SC Freiburg. He was released in June 2011 after Bayern's reserves were relegated from the 3. Liga.
On 21 January 2014, Sansone along with teammates Pedro Mendes and Aleandro Rosi joined Sassuolo from fellow Serie A club Parma. Sansone and Mendes both signed co-ownership deals, for €2.5 million and €500,000 respectively. Rosi however made a loan switch from Parma to Sassuolo, as part of the swap with Jonathan Rossini also in temporary deal.
In June 2014 Raman Chibsah and Sansone joined Sassuolo outright for an additional €5.75 million from Parma, as well as Parma bought back Mendes for €2.5 million.
On 7 August 2016, Sansone signed with Villarreal on a five-year contract reported to be in the region of €13 million. He made his club debut in a 1–1 away draw against Granada in La Liga, on 20 August, and scored his first goal for the club in a 2–0 away win over Málaga in La Liga, on 10 September.
Sansone made his U17 debut in November 2007 along with Bayern teammate Roberto Soriano. Both players also called up to 2008 Minsk under-17 International Tournament He scored a goal in the second match, a 3–0 won against Belarus. However, he was not called up to 2008 UEFA European Under-17 Football Championship elite round in March.
He played for Italy U19 team on 11 March 2009, the second match of season 2009–10 (for player born on or after 1991), he also called up to the next friendly match against Ukraine (born 1990 team), as Ukraine was preparing for the 2009 final tournament. He scored a goal in that match, a 2–2 draw. He then dropped from the team, as he did not receive a call-up to U18 team (born 1991 class) for a friendly tournament in Slovakia. In November 2009, he was recalled to the U19 team for 2010 UEFA European Under-19 Football Championship qualification. He replaced captain Jacopo Sala in the first match, then started in the next two matches as wing forward, partnered with forward Mattia Destro and Nicolao Dumitru against San Marino, ahead Marco D'Alessandro who started in the first match. In the last match against Republic of Ireland, Sansone partnered with Destro in a 442 formation. Sansone then selected in 1 of the 3 friendly matches before the 2010 UEFA European Under-19 Football Championship elite qualification, but never received call-up again, as some of the players were recovered from injury and some players returned from U21 team (Fabio Borini and midfielder Soriano, etc.).
Sansone made his U20 debut in February 2012. He also played an unofficial friendly against Italy under-21 Serie B representative team in December 2011.
On 31 May 2015 Sansone received his first senior national team call-up from Antonio Conte.
On 16 June 2015, Sansone debuted for the senior team after being substituted on for Stephan El Shaarawy in the 68th minute in a friendly to a 1–0 defeat to Portugal.
Sansone is a fast and agile forward with a slender physique and an eye for goal. He possesses good technique and dribbling skills, which enable him to take on opponents in one on one situations. He is capable of playing as a second striker, but his preferred position is as a left winger, a position which allows him to cut into the centre to strike on goal with his favoured right foot or make attacking runs into the area in order to create space for teammates.As of 22 May 2017
As of match played on 15 November 2016.