Roundtrip St. Louis to San Juan Airfare on United or American Airlines

No special codes or coupons are required. This roundtrip airfare deal is available on Expedia and expires on August 31, 2026.

This is a basic economy fare with one stop.

• On American Airlines, you may have a personal item and a carry-on bag.
• On United Airlines, you may have a personal item.
  • Please note there is no seat selection, no carry-on bag, and no changes allowed with United’s basic economy fare. However, if traveling with children, you will be seated together per airline policy.

Travel Availability

• Departs STL: Nov 8-11, 14-18; Dec 7-9, 31; Jan 4, 11, 18-21, 24-28, 30-31; Feb 1-4, 6-10, 22-25; March 1-3, 10, 17, 23-24, 31; April 1, 4, 7-8, 11, 13-14, 19-22, 25-29; May 2-6, 9-13, 19-20, 24-31; June 1-2, 5, 8, 13, 15-16, 22, 27, 29-30; July 4, 14, 18, 20, 22, 24, 27-28; Aug 1, 3-4, 7-12, 14-19, 21-26, 29-31
• Departs SJU: Nov 6-8, 12-14, 18-21, 26; Dec 3-6, 8-13, 15-18, 21, 24-25; Jan 14-17, 20-25, 27-30; Feb 3-7, 10-14, 18-19, 25-27; March 4-6, 11, 25; April 8-9, 15, 22-23, 29-30; May 1-2, 5-7, 9, 12-14, 16, 19-24, 27-29; June 2-6, 9-13, 16-18; July 14-17, 21, 29-30; Aug 5-6, 19, 26-27