On 19 August 2019, Coutinho joined German club Bayern Munich on a season-long loan. Bayern paid a loan-fee of €8.5 million plus Coutinho's wages. Bayern reportedly had the option to sign Coutinho on a permanent contract in the summer of 2020 for €120 million. On 24 August 2019, Coutinho made his Bundesliga debut for Bayern in a 3–0 win at Schalke. Coutinho came on as a 57th minute substitute. On 21 September, Coutinho scored his first goal for Bayern in a 4–0 win against 1. FC Köln. Coutinho admitted in a press conference that he is happy at Bayern Munich and intends to stay there. On 14 December, Coutinho scored his first hat-trick for Bayern Munich, also assisting two goals, in a 6–1 win over SV Werder Bremen. On 14 August, Coutinho came on in the second half of their Champions League quarter-final match against his parent club Barcelona, assisting Robert Lewandowski in the 82nd minute for the 6th goal and scoring the last 2 goals at 85th and 89th minutes to complete the 8–2 routing. Later on, Coutinho came on as a substitute in the Champions League Final, in which Bayern Munich managed to win 1–0 over Paris Saint-Germain, to be their second treble of Bundesliga, DFB-Pokal and Champions League titles.