Huffman added, "We are committed to working with you to combat the bad actors, abusive behaviors, and toxic communities that undermine our mission and exist exclusively to get in the way of the creativity, discussions, and communities that bring us all to Reddit in the first place".
Reddit said they were banned for violating several rules aimed at preventing attacks on marginalized groups or vulnerable communities, as well as vote manipulation and interfering with Reddit's operations.
Chief executive Steve Huffman said in a post that communities and users who had promoted hate based on identity or vulnerability would be banned.
The company said that Trump violated its rules against hate by rebroadcasting his 2016 campaign launch rally, in which he smeared Mexican immigrants to the USA as "rapists" and criminals.
During that rally, Trump called some people entering the country from Mexico "rapists" and said they were "bringing crime". "And some, I assume, are good people".
In comments to The Verge, Twitch said that all content creators on the platform are subject to the same rules.
A Twitch spokeswoman said the platform had told "the president's team" past year that there were no exceptions on the site for political or newsworthy content that broke its rules.
President Trump has been posting videos of his little gatherings and it appears someone has reported them to Twitch for racist language and the account has been suspended. A White House spokesperson did not offer comment.
The move comes with online platforms facing pressure to crack down on hateful content, including from the president, amid a broad movement to address racial equity in the wake of police killings of African-Americans. Twitter has begun to put warning labels on President Trump's tweets that are in violation of its policies.
But the debate about whether to penalize rule-breaking content from the president and his supporters is also dragging in a host of other social media platforms. In a surprise twist, Donald Trump's Twitch has been temporarily banned for hateful conduct from previous streams and events.
Reddit says that it has banned about 2,000 subreddits for violating the more stringent rules regarding hate speech and racism, but only about 200 of them have more than 10 daily users.