Bezos, 57, and Sanchez, 51, shared a kiss while on a walk around the city. The couple had enjoyed a day of shopping and shared a meal with Sanchez's ex, Tony Gonzalez.
Gonzalez' family also joined for the occasion. Sanchez and Gonzalez were together in the 2000s and share a son, Nikko.
Bezos and Sanchez had been in New York just a day after celebrating William Shatner's successful space voyage.
Sanchez has shared photos from Wednesday's launch on social media. Bezos and the former news anchor were both at the site to see Shatner's launch.
Sanchez also penned a sweet note to Bezos on Instagram ahead of the launch.
"Good luck on the launch my love," she captioned a photo of Bezos on a horse. "This morning you and your @blueorigin team will be launching 4 incredible people into space, just yards away from where we were riding horses yesterday. Truly incredible! You never cease to amaze me."
Shatner was joined by Blue Origin Vice President of New Shepard Mission and Flight Operations Audrey Powers as well as Dr. Chris Boshuizen and Glen de Vries.