Titmus is the defending Olympic gold medalist, while Ledecky topped the podium in Rio.
After a star-studded Opening Ceremony, the games continue Saturday, headlined by Katie Ledecky and the Women's Swimming tea
The U.S.
Will Taylor Swift be in Paris, France for the Summer Olympics?
All the updates as Argentina came back from two goals down to draw with Morocco in Group B of Olympic men's football.
See LeBron James, Steph Curry, Jayson Tatum and Team USA men's basketball on the road to the Paris Olympics 2024.
It's the United States vs. Australia in the USA Basketball Showcase exhibition ahead of the 2024 Paris Olympics at 11 a.m.
Team USA takes on Canada on Wednesday in the first of five exhibition games ahead of the 2024 Paris Olympics.