Sinéad O'Connor became both an icon and and an industry outcast after her protest against the Catholic Church. Here are 5 other times the singer stood up for what she believed in.

Aside from an appearance on "Late Night with David Letterman" the year before, the 1989 Grammys was the first time O'Connor, then just 21 years old, found herself on a global stage, with millions of people paying attention to her.

The year also marked the first time the Grammys presented an award for best rap performance, relenting to the fact that rap music was not a fad but a musical expression that should be recognized alongside pop, rock, and country.

However, the Recording Academy's acceptance only went so far and its bosses decided to not televise the award, resulting in a boycott from rappers, including the category's inaugural winners DJ Jazzy Jeff & The Fresh Prince (aka Jeff Townes and Will Smith).

O'Connor, who was a big fan of hip-hop music and had enlisted rap artists to support her on her first US tour, decided to show her solidarity by painting the man in the crosshairs logo of the rap group Public Enemy — which frontman Chuck D said symbolizes the Black man in America — on the side of her head ahead of the performance.

By doing so, in her performance of her college radio hit "Mandinka" she forced the Grammys and its audience to confront the erasure of rap artists who had not only been left out of the awards show, but mainstream television channels and radio stations as a whole.

O'Connor was 20 when she welcomed her first child, a son she named Jake, with music producer John Reynolds, who she later married.

Jake was born in 1987, three weeks before the release of O'Connor's debut album. As O'Connor wrote in her 2021 memoir "Rememberings," her record label encouraged her to terminate her pregnancy as they thought being a mother would give her a negative image.

"If I was going to be a musician I ought not to have babies because a woman shouldn't leave her baby to go on tour and at the same time a child can't be taken on tour," she recalled a doctor telling her, on the instruction of Ensign Records label executive, Nigel Grainge.

"Your record company has spent £100,000 recording your album. You owe it to them not to have this baby," she alleged the doctor also said in an attempt to get her to agree to an abortion.

According to Vulture, O'Connor's decision to wear a onesie belonging to her then-16-month-old son around her waist along with her crop top, baggy, low-slung jeans, and Doc Martens at the Grammys was a "a middle finger" to those who told her motherhood would end her career.

O'Connor withdrew from a 1990 appearance on the NBC variety sketch show after learning that the comedian Andrew Dice Clay, who was known at the time for his deliberately offensive on-stage persona known as "The Diceman," was scheduled to host.

"It would be nonsensical of 'Saturday Night Live' to expect a woman to perform songs about a woman's experience after a monologue by Andrew Dice Clay," the then-23-year-old O'Connor said in a statement at the time, per The Los Angeles Times.

She added that to perform alongside one of Clay's comedy routines, which featured jokes about sexual violence, would show "disrespect to women."

O'Connor wasn't the only one to boycott the episode. "SNL" cast member Nora Dunn also announced that she would not appear.

At a 9,000-person strong concert at the Garden State Arts Center in New Jersey, O'Connor refused to take to the stage until the organizers agreed not to play "The Star Spangled Banner" before the show.

According to The Washington Post, the venue had a policy of playing the US national anthem before every event but eventually relented fearing that a last-minute cancellation would enrage the audience. They prohibited the singer from performing there again.

When the news got out, she ended up being banned from several radio stations in New York and New Jersey.

O'Connor said at the time that national anthems "have nothing to do with music in general" but later expanded on her reasons during an acceptance speech at the Grammys that year where she picked up three major awards.

She told the audience of her reasons for not wanting "The Star Spangled Banner" played at her gigs: "It's the American system I have disrespect for, which imposes censorship on people, which as far as I'm concerned is racism."

"I didn't want to to go onstage after the national anthem of a country that's harassing people when they perform at gigs," she said.

In 2013, former Disney Channel star Miley Cyrus cited O'Connor's video for "Nothing Compares 2 U" as an inspiration for her own music video, "Wrecking Ball." In response, O'Connor penned an open letter to the then-20-year-old pop star, expressing her concern about Cyrus' choice to be "naked and licking sledgehammers" in the video.

In the lengthy letter, she essentially advised Cyrus not to "prostitute" herself to the music industry.

"It is in fact the case that you will obscure your talent by allowing yourself to be pimped, whether it's the music business or yourself doing the pimping," O'Connor wrote.

Speaking from experience, O'Connor added: "The music business doesn't give a shit about you, or any of us. They will prostitute you for all you are worth, and cleverly make you think its what YOU wanted."

After O'Connor's letter, things ended up getting ugly between the two: Cyrus shared old tweets of O'Connor's asking for psychiatrist recommendations and O'Connor in turn sent two additional letters and threatened legal action.