Early career Born in
Arbúcies,
Girona,
Catalonia, to Senegalese parents, Keita came up through the
FC Barcelona's youth academy. In 2010, Keita travelled with the Barcelona youth team to
Qatar for a tournament, where he played a
practical joke by placing an ice-cube in a teammate's bed; As a punishment, Barcelona sent the 15-year-old Keita on loan to satellite club
UE Cornellà, despite his reputation as a future prospect for the first team. The loan meant Cornellà held the rights to a fraction of Keita's playing rights. After a season in which he scored 47 goals for Cornellà's youth side, Keita turned down the chance to return to Barcelona, attracting the interest of
Real Madrid and
Manchester United. Keita was unable to play official matches for Lazio's youth sides for a year, as he had to wait to be granted Spanish citizenship and the EU passport required for the Italian club to register him. However, he impressed while playing in the
Torneo Karol Wojtyla youth competition, where he scored six goals in just four matches. Five days later, Keita made his debut in the
Europa League group stage match against
Legia Warsaw, starting and providing the match's only goal scored by
Hernanes. On 10 November 2013, he scored his first senior goal in a 1–1 draw against
Parma. On 18 August 2015, Keita came off the bench to score the only goal of the game as Lazio beat
Bayer Leverkusen 1–0 in the first leg of their
Champions League play-off at the
Stadio Olimpico. Keita fully established himself in the starting lineup in the
2016–17 season, scoring his first goal of the season in
Serie A matchday 6 against
Empoli at home. On 6 March of the following year, Keita made his 100th Serie A appearance in the 2–0 win at
Bologna. Later on 23 April, Keita scored his maiden hat-trick, contributing in Lazio's 6–2 thrashing of
Palermo, taking his tally up to 11 goals, reaching double figures for the first time in his career. He completed the hat-trick in five minutes, making it the fastest hat-trick scored in Serie A since
1974–75 season. One week later, in the
Derby della Capitale against
Roma for the matchday 34, Keita scored a brace, as Lazio won 3–1, the first win in the league against them since November 2012. He also become the first Lazio player to score a brace in the derby since
Roberto Mancini in
1998–99 season.
Monaco On 29 August 2017, Keita joined
Monaco on a five-year contract for a reported €30 million transfer fee. He was assigned the number 14 shirt vacated by
Tiémoué Bakayoko, who left for
Chelsea earlier that summer. On 21 October 2017, Keita opened the scoring in the 2–0 Ligue 1 home win over
Caen to register his first competitive Monaco goal after playing seven matches in all competitions for the club.
Loan to Inter Milan On 13 August 2018, Keita signed for
Inter Milan on loan of €6 million with a €30 million option to buy at the end of the season. He made his Serie A debut for the club on the first matchday of the 2018–19 season, in a loss to
Sassuolo. On 24 November, he scored his first goals for the
Nerazzurri; a brace in a 3–0 win over
Frosinone. While not making many appearances, he found his way to the net again on 3 December in the away match against Roma, which ended 2–2. On 29 December, he scored the 1–0 winner over Empoli in the 72nd minute off a pass from
Šime Vrsaljko. During the second half of the season he scored one goal, also against Empoli, on 26 May 2019, the opening goal in a 2–1 win for Inter Milan. At the end of the season, Baldé returned to Monaco as Inter did not trigger the buyout clause.
Loan to Sampdoria On 29 September 2020, Keita joined
Sampdoria on loan until 30 June 2021. On 23 December, after being sidelined for almost two months due to an injury, he scored his first goal for Sampdoria in his fourth appearance, in the 2–3 home defeat against Sassuolo, a game in which he was also sent off.
Cagliari On 31 August 2021, Keita joined then-
Serie A side Cagliari, where he played for one season.
Spartak Moscow On 26 August 2022, Keita signed a three-year contract with
Russian Premier League club
Spartak Moscow. He made his debut on 4 September in a 1–2 loss to
Zenit Saint Petersburg. On 17 September 2022, it was announced that the
Italian Anti-Doping Organization concluded an investigation into Balde's actions from the time he was playing for Cagliari and banned him from playing until 5 December 2022 for violating testing procedures, despite no banned substances being found. Spartak announced it would comply with the decision taken in Italy. On 4 April 2023, Baldé scored his first goal for Spartak in a 1-2
cup loss to
Ural Yekaterinburg.
Loan to Espanyol On 1 September 2023, Keita was moved to
Espanyol back in his home country on loan for the
2023–24 season.
Release by Spartak On 6 July 2024, Baldé's contract with Spartak was terminated by mutual consent.
Sivasspor On 13 August 2024, Baldé signed a two-year contract with
Sivasspor in Turkey.
Monza On 13 February 2025, Baldé signed a contract with
Serie A club
Monza until the remainder of the
2024–25 season. ==International career==