Oscar Otte is mainly active on the ITF Future Tour and since 2017 more often on the ATP Challenger Tour . On the Future Tour he has so far won eight titles in singles and 15 more in doubles, twelve of them with his Cologne club mate Andreas Mies .
At the beginning of 2017 Otte was able to win three futures in a row, which meant that he was now in 358th place in the world rankings and at the end of April at a Challenger tournament, the China International Challenger Qingdao 2017 in Qingdao , China, surprisingly reached the finals as a qualifier, where he was Janko Tipsarević was subject. Before the tournament, he managed only one victory on the Challenger level. He also reached the final in doubles with Mies. The following week, Otte reached the semi-finals in Kunming , the best-endowed challenge tournament with $ 150,000 , where he was defeated by Quentin Halys in three sets. He increased his world rankings to 223th place. Two weeks later he was finally able to win his first Challenger title in Rome alongside Andreas Mies in doubles. He won his first individual title in Lisbon when he defeated the top 100 player Taro Daniel in three sets in the final .
Otte has been playing for the KTHC Stadion Rot-Weiss since 2011 . In 2011 he was relegated to the regional league with Cologne from the 2nd Bundesliga . In 2014 , with the KTHC as a promoter from the regional league, he managed to march through the 2nd division and advance to the 1st Bundesliga , where he played in 2015 and 2016 . In his Bundesliga record of 45 matches in singles and doubles, 31 wins stand against 14 defeats. Of his singles, he won 16 games in only six defeats, of 23 doubles he won 15 in eight defeats.