"We strongly condemn anti-Semitism, and hateful conduct has absolutely no place on our service," said a Twitter spokesperson in a statement Wednesday.
"We also have a robust 'glorification of violence' policy in place and take action against content that glorifies or praises historical acts of violence and genocide, including the Holocaust."
Around 6 million Jews were systematically murdered by Nazi Germany during the Holocaust, which started in 1941 and ended in 1945.
British rapper Wiley was banned from Twitter in July after he posted a series of anti-Semitic tweets. Tweets from Wiley's account asserted that Jews have systematically exploited Black musicians. In one tweet, which has now been deleted, he compared Jews to the Ku Klux Klan.
On Monday, Facebook announced that it will ban content that "denies or distorts the Holocaust," reversing its earlier policy. The company said it introduced the change after noticing a rise in anti-Semitism.
In a 2018 podcast interview, CEO Mark Zuckerberg said Facebook didn't remove Holocaust-denying content because it must allow for the possibility that users are making unintentional mistakes. "I don't think that they're intentionally getting it wrong," Zuckerberg said of users who shared that type of content.
In announcing the change, Facebook said: "Our decision is supported by the well-documented rise in anti-Semitism globally and the alarming level of ignorance about the Holocaust, especially among young people."
On Monday, actor and comedian Sacha Baron Cohen wrote on Twitter that "Facebook should have banned Holocaust denial long ago, but better late than never."
He called on Twitter, YouTube, Reddit and Google to do the same, saying it was "not a hard call."
—CNBC's Michelle Gao contributed to this article.