Thiem played at the Hamburg Open as the top seed, losing in the quarterfinals to Andrey Rublev. The following week he won the 14th title of his career at the Austrian Open defeating Albert Ramos Viñolas in straight sets in the final. At the Rogers Cup, he reached the quarterfinals before losing to Medvedev. He then competed at the US Open and was upset by Thomas Fabbiano in the first round. In the Davis Cup he won one singles rubber and lost the other as Austria won the tie against Finland 3–2. At the Laver Cup, he won against Denis Shapovalov, but lost to Taylor Fritz. Team Europe won the event. At the China Open, Thiem defeated Stefanos Tsitsipas to win his first title in Asia. At the Shanghai Masters Thiem reached the quarterfinals before being bested by Matteo Berrettini. Thiem triumphed over Schwartzman to claim the Vienna Open trophy for the first time in nine attempts. At the Paris Masters, he lost to Dimitrov in the third round.
