Thiago Seyboth Wild started playing tennis when he was 5 years old. He already celebrated successes on the junior tour. He has played on this since 2015 and was able to achieve his best result in the junior world rankings with rank 8 in early 2018, shortly before his status as a junior expired. At Grand Slam tournaments for juniors, his best result was reaching the quarter-finals at the French Open 2017 in singles and the semifinals of the US Open in doubles in the same year.
Seyboth Wild played for the first time in 2014, so far mainly on the third-rate ITF Future Tour . There he achieved his first title in 2017 in Antalya with victory in singles and doubles. In Rio he also got his first victory in the next higher tournament category, the ATP Challenger Tour . He ended the year for the first time with a place in the world rankings . He was ranked 605 in singles and outside the top 1000 in doubles. In 2018, the tournament administration in São Paulo awarded him a wildcard in singles. Thus it came to its premiere on the ATP World Tour . In the first round he lost against the Argentine Carlos Berlocq after leading the set.
He celebrated his first success on the Challenger Tour in November 2019 in Guayaquil . In the final he defeated the top seeded Bolivian Hugo Dellien in two sets. Through this success he reached a new career high with the 235th place. On the ATP Tour he celebrated his first individual title in Santiago de Chile , where he was allowed to start thanks to a wildcard. In the final, he beat the second seeded Norwegian Casper Ruud in three sets and became the youngest Brazilian to win an ATP title.