Born in Sant Jaume dels Domenys, Tarragona, Catalonia, Bartra joined Espanyol as a child before moving to Barcelona's youth system, La Masia, at age 11.

[2] Bartra made his first-team debut on 14 February 2010, coming on as a substitute for Jeffrén Suárez for the final 30 minutes of a 2–1 loss to Atlético Madrid at the Vicente Calderón Stadium.

[5] In the 2012–13 campaign, Bartra joined the first team squad permanently, but manager Tito Vilanova tended to field Javier Mascherano, Alex Song and Adriano ahead of him,[6][7][8] and only appeared in 16 matches in all competitions.

[9] On 16 April 2014, in the final of the Copa del Rey against Real Madrid, with five minutes remaining, Gareth Bale outsprinted Bartra from the halfway line – with the former running off the field at one point – before scoring the 2–1 winner.

[15][16] He made his competitive debut on 14 August, playing the entire 2–0 loss against Bayern Munich in the DFL-Supercup,[17] and a month later scored his first goal in a 6–0 victory at Legia Warsaw in the group stage of the UEFA Champions League.

[25] Bartra's first match after returning took place on 20 May 2017, and he played the entire 4–3 home win over Werder Bremen[26]– he had also been an unused substitute in the previous fixture against FC Augsburg.

[33][34] He made his debut two days later in the Champions League play-off first leg away to Copenhagen, as a substitute in a 2–1 loss;[35] his first goal on 18 September came in added time to win 3–2 at home to Gaziantep.

[41] This game was later annulled by FIFA as they had not been notified early enough that the referee would be from Equatorial Guinea,[42] and his first valid appearance took place on 8 September 2014 as he came on as a 68th-minute substitute for Sergio Ramos in a 5–1 home victory against Macedonia for the UEFA Euro 2016 qualifiers.