The Miami Heat player shared the news Saturday posting a picture of the 40-year-old actress wearing a beautiful 8.5 carat cushion cut diamond designed by Jason of Beverly Hills.
"She said YES!!! @gabunion," Wade captioned the pic.
Union also shared a photo of her big rock on the image sharing site, writing, "Sooooo this happened... #Yessss."
The couple has been dating since 2009. Last summer, the Heat shooting guard told Oprah Winfrey that the Think Like a Man Too star made his eyes sparkle.
"The biggest time she makes my eyes sparkle is when Zaire [his 11-year-old son from a previous marriage] comes home and homework is a little hard that day, so he's stressing, and she goes to the table with him and she sits down until he gets it."
"And at that time my heart is smiling a little bigger that day because I know her love is deeper than just me," he added.