Celebrities are constantly sharing their thoughts on social media, and while for the most part it's entertaining for fans, sometimes their posts spark controversy.

As a result, the stars find themselves facing major backlash.

Here are the ones that had us talking throughout the year:

Kim Kardashian

Kim Kardashian came under fire on Halloween for calling people who didn't recognize her costume the R-word. (AP)

Kim Kardashian came under fire on Halloween for calling people who didn't recognize her costume the R-word.

On Oct. 31, the "Keeping Up with the Kardashians" star documented herself on Instagram at her sister Kendall Jenner's Halloween party asking guests if they knew who she and best friend Jonathan Cheben were dressed up as.

“OK guys, we are Pam Anderson and Tommy Lee,” Kardashian, 38, said according to People.

“Nobody knows who we are here!" she continued. "You guys are all too f--king young. This is so sad.”

Per People, in a separate video, the KKW Beauty mogul is heard telling former assistant Stephanie Shepherd: “Nobody knows who I am. Yeah! R----d."

Fans immediately took to Twitter to express their distaste with the reality star's remark, which prompted Kardashian to take down the video and apologize.

"I want to apologize for what I said in a recent video post that is inappropriate and insensitive to the special needs community," she said in a statement to E! News.

"I try to learn from my mistakes, and this is one of those times. Please know that my intention is always pure, and in this case, it was a mistake. I'm sorry."

Bette Midler

Bette Midler found herself in hot water in November for showing disrespect to first lady Melania Trump.

In November, the 72-year-old actress posted a picture on Twitter of Melania posing in a cockpit for a GQ photo shoot, and included a vulgar, insulting caption.

"The dry cleaning bill for the upholstery on Air Force One must be insane. #FLOT--S," Midler wrote.

Social media users immediately went on Twitter to slam the star and called on her to apologize to the first lady.

"Why are you doing this? Haven’t you had enough of bashing this poor woman? She was a model, so what. Don’t hate. You really just made a fool of yourself with such a catty comment. Did you feel better after posting this? That made you feel good? You should apologize," one Twitter user wrote.

Armie Hammer

Armie Hammer was slammed for his tweet criticizing other celebrities' tributes to legendary Marvel superheroes creator, Stan Lee. (Getty Images)

Armie Hammer faced backlash after he criticized celebrities for their tributes to Stan Lee following the death of the legendary Marvel superheroes creator in November.

"So touched by all of the celebrities posting pictures of themselves with Stan Lee... no better way to commemorate an absolute legend than putting up a picture of yourself," Hammer wrote in a since-deleted tweet.

Social media users immediately slammed Hammer for criticizing how others grieved a person’s death. Many people said the photos may have captured a good memory they had with Lee that they wanted to share publicly.

Following the backlash, Hammer issued an apology.

“While attempting to provide some unnecessary social commentary about the current selfie culture, I (in true a--hat form – thank you Jeffrey Dean Morgan) inadvertently offended many who were genuinely grieving the loss of a true icon,” the 32-year-old actor wrote.

“I want to apologize from the bottom of my heart and will be working on my Twitter impulse control.”

 

Roseanne Barr

In May, Roseanne Barr posted a racist tweet about former President Obama's aide Valerie Jarrett, stating that Jarrett, an African-American who was born in Iran, is like the “muslim brotherhood & planet of the apes had a baby.”

Barr, 66, immediately faced massive backlash, and her namesake show was canceled just hours after, with ABC Entertainment president Channing Dungey saying the network would not produce the second season of the "Roseanne" reboot.

"Roseanne's Twitter statement is abhorrent, repugnant and inconsistent with our values, and we have decided to cancel her show," Dungey told Fox News at the time.

In response, Barr apologized and quit Twitter.

"I apologize to Valerie Jarrett and to all Americans. I am truly sorry for making a bad joke about her politics and her looks. I should have known better. Forgive me — my joke was in bad taste," she wrote. She has since rejoined the social media site.

Patrick J. Adams

In May, actor Patrick J. Adams issued an apology after fans accused him of body shaming a woman in his social media post. (Getty)

After attending the royal wedding in May, “Suits” star and former on-screen husband of Meghan Markle, Patrick J. Adams came under fire for body shaming a woman in a social media post.

According to screenshots captured by some tabloids at the time, a woman reportedly saw Adams in a newspaper attending the wedding and chose to tell him that she found the photo of him and his wife, Troian Bellisario, “terrible” explaining that he looked “chunky.”

When she later fell asleep at the airport the 37-year-old actor posted her image, prompting fans and critics alike to accuse him of body-shaming her in retaliation for her rudeness.

After apparently mulling it over, Adams took the photo down and replaced it with an apology message on Instagram.

PewDiePie

YouTube star PewDiePie apologized in July for posting a controversial meme, which reportedly mocked pop star Demi Lovato’s apparent overdose. (iStock)

Earlier this year, YouTube star PewDiePie apologized for a controversial meme he posted that reportedly mocked pop star Demi Lovato’s apparent overdose.

PewDiePie, whose real name is Felix Kjellberg, shared a now-deleted meme in July that allegedly showed Lovato asking her mother for money to purchase a burger, but then spending the cash on heroin, CNET reported at the time.

Heroin is the drug TMZ initially reported was the cause of the singer’s alleged overdose, though a source later told Fox News that “it’s not heroin.”

"Deleted meme. I didn't mean anything with it and I didn't fully know about the situation. I realize now it was insensitive, sorry!” the YouTuber said after he received backlash from many of Lovato's fans.

Lorde

Lorde arrives to attend the 2018 MusiCares Person of the Year show honoring Fleetwood Mac at Radio City Music Hall in Manhattan, New York, U.S., January 26, 2018.

Lorde was blasted by social media users in April after she posted a photo of a bathtub with Whitney Houston references. (Reuters)

Earlier this year, New Zealand pop star Lorde was slammed by social media users for using Whitney Houston lyrics as a caption for an Instagram picture she posted of a bathtub, a reference to the singer’s drowning death.

“And iiii will always love you," Lorde wrote on Instagram in April along with a photo of a luxurious bathtub. The lyrics are from one of Houston’s biggest hits — her cover of Dolly Parton’s “I Will Always Love You.”

Social media users slammed the “Royals” singer for the post, which many deemed as insensitive.

“Whitney Houston & her daughter both overdosed in bathtubs. If Lorde truly didn’t know then okay but it’s not believable,” one person wrote.

The photo along with Lorde's apology have since been taken down from her Instagram page.