Katerina Siniaková won her first WTA singles title at Shenzhen Open. In the second round, she edged world No. 4 Simona Halep in three sets (7-5 in the third) and claimed first win over a top-10 player.
In February 2017, she was nominated to the Fed Cup team for the first time by the captain Petr Pála as she was the third best ranked woman Czech tennis player (considering Petra Kvitová's injury) after Karolína Plísková and Barbora Strýcová.
She was ranked the world No. 2 junior tennis player in December 2012. With fellow Czech Barbora Krejcíková, she won the girls' doubles titles at the French Open, at Wimbledon and the US Open in 2013.