Westbrook welcomed Skye and Jordyn on Sunday. He announced their arrival on social media.
"11.16.18.," the Thunder star wrote for the caption on a close-up photo of the newborns.
Westbrook did not play in the Thunder's 110-100 win against the Phoenix Suns on Saturday in Phoenix. He has missed the last five games due to a left ankle sprain.
Westbrook welcomed the twins with wife Nina Westbrook. The couple also parent 18-month-old Noah.
"Mommies girls are here and healthy," Nina Westbrook wrote on Instagram.
Westbrook turned 30-years-old on Nov. 12. The seven-time All-Star and 2016-17 NBA MVP is averaging 24.1 points, 8.9 assists and 8.3 rebounds per game this season, after averaging a triple-double in each of the two previous seasons. The superstar guard is signed through 2021, with a $46.6 million option for 2022.