Minaj received a raft of backlash after making her relationship Instagram official last year, when it was discovered Petty was a registered sex offender in New York.
Now less than a year on, the 'Starships' singer has shared the news of her secret wedding with her 106 million Instagram followers with a post captioned: "Onika Tanya Maraj-Petty 10.21.19".
The video, which has earned over 4 million views in 18 hours, shows two mugs that say 'Mr' and 'Mrs' and two hats that read 'Bride' and 'Groom'.
The news comes after Minaj tweeted she had decided to "retire and have her family" in September.
According to TMZ, public records show that Petty was charged with attempted rape of a 16-year-old girl in 1995, when he was also 16.
Court records indicate that he served nearly four years for that crime, before being convicted of first-degree manslaughter in 2006. He was released from prison in 2013.
Minaj hit back at fans that criticised her relationship last year, writing "y'all can't run my life," in response to a comment on social media.
"He was 15, she was 16... in a relationship," she wrote of Petty's conviction, according to Cosmopolitan.
The rapper has previously come under fire for collaborating with convicted criminals such as Tekashi 6ix9ine, who pleaded guilty to filming a 13-year-old child engaged in a sexual act with a grown man in 2015.