The Anaconda hitmaker, who only confirmed she is dating the rapper two months ago, was flooded by messages of congratulations after she showed off her large heart-shaped white and yellow diamond engagement ring on Instagram on Wednesday.
The 32-year-old singer, who split from Safaree Samuels in late 2014 after 12 years of dating, sent fans into a frenzy a few hours earlier when she posted a diamond ring emotion on Twitter, writing: "I'll post it later."
Nicki first sparked rumours she is set to tie the knot on Tuesday night, when she wrote on social media: "I wish every night could feel like last night."
The Only hitmaker revealed last year that she would be disappointed if she never had children, but wanted to get married first.
She said: "I want to make sure I do it in that order. I've always felt like that since I was young; my mother always put that in my head."
The couple denied they were dating when they were first linked in December, but Meek - whose real name is Robert Rahmeek Williams - recently admitted he is smitten with the star.
He told the spring issue of XXL magazine: "Yeah, that's my baby right there. S**t real. Yeah, I tell her that. I'm like, 'I don't really hold hands, but like, I'll hold hands with you.' She know that”.
"Like, I don't really do things, but certain people make you do certain little stuff and it be like, 'S**t, I don't care.' They can catch me in the pictures doing anything nowadays, holding an umbrella for Nicki, you know what I'm saying? I got the girl that I wanted, not what they wanted, you know what I'm saying? What I wanted."