The longtime couple shared the exciting news on their individual Instagram accounts on Saturday, March 9.
Alex, 43, posted a pic of him holding onto his ladylove's hand that included one heck of an engagement ring. "she said yes" was the caption.
Jennifer, 49, shared the same photo. The caption for her pic was simply a bunch of heart emojis.
Celebs like Busy Philips, Ashley Graham and Selma Blair have left heartwarming messages for Jennifer and Alex on their engagement post.
Jennifer was previously married to Ojani Noa, Cris Judd and Marc Anthony. She and Marc have 10-year-old twins together named Max and Emme.
Alex married Cynthia Scurtis in 2002 and got divorced six years later. They share two daughters: 14-year-old Natasha and 10-year-old Ella.
Congrats to the happy twosome!