Gnabry started his career in England with Arsenal in the Premier League, making his professional debut in September 2012.

The following season, Gnabry scored 23 goals as Bayern sealed a continental treble consisting of the Bundesliga, DFB-Pokal and UEFA Champions League.

After appearing for Germany at various youth levels, Gnabry made his senior international debut in November 2016 in a 2018 FIFA World Cup qualification match against San Marino, scoring a hat-trick in an 8–0 win.

[15] Four days later, he made his UEFA Champions League debut, coming on as a substitute in Arsenal's 2–0 home loss to Schalke 04.

[17] He then made his first start for the club on 22 September 2013 in the Premier League against Stoke City after Theo Walcott was ruled out just before kick-off.

[20] Gnabry's impressive start to the season resulted in a nomination for the 2013 Golden Boy Award,[21] and a new five-year contract with Arsenal.

[27] On 7 August 2015, Gnabry joined West Bromwich Albion on a season-long loan to gain first-team experience.

[29] However, he did not make any further league appearances, with manager Tony Pulis stating in October that Gnabry was "not at the required level" to play for West Brom.

[32] On 31 August 2016, Gnabry signed for Bundesliga club Werder Bremen for a reported transfer fee of £5 million.

[37] In his single season at the club, he made 27 league appearances scoring 11 goals[38] while Werder Bremen finished 8th in the Bundesliga.

[46] On 1 September, Gnabry made his Bundesliga debut for Bayern Munich in a 3–0 win at Stuttgart when he came on as a substitute in the 77th minute.

[49] On 2 March 2019, Gnabry scored Bayern Munich's 4000th Bundesliga goal during a 5–1 win over Gladbach, helping the club become the first team to achieve the milestone.

[citation needed] On 1 October 2019, Gnabry scored four goals in the 2019–20 UEFA Champions League 7–2 away win against Tottenham Hotspur.

[57] Bayern won 1–0 over Paris Saint-Germain in the final, to be his first Champions League title along with his teammate Joshua Kimmich, another VfB Stuttgart academy product.

[71] Three days later, he tripled his tally by putting two past South Korea, the second being a stoppage time free kick that helped Germany salvage a point in a 3–3 draw.

[74] He ended the tournament as the joint top scorer along with his teammate Nils Petersen,[75] helping Germany to win the silver medal.

[78] On 9 October 2019, during a 2–2 friendly international draw with Argentina, Gnabry became the fastest player to reach 10 goals for the nation, doing so in his 11th appearance and beating Miroslav Klose's record by 2 games.

He later battled for fitness and first-team minutes, so he was loaned out to West Bromwich, where manager Tony Pulis mentioned that he was not ready for top-flight football,[83] and was not good enough to play at the Hawthorns.

"[86] His coach at Werder Bremen, Alexander Nouri, said: "He is lightning quick, a clinical finisher, but he puts a lot of work now into his defence... now he's making these deep runs back to his own box defending.