The social media giant said it will block URL’s associated with QAnon from being shared on Twitter and would stop recommending and highlighting content and accounts associated with the group - in search and conversations.
The suspensions, to be rolled out this week, will hit approximately 150,000 accounts worldwide with more than 7,000 permanently removed from the platform.
What is QAnon?
QAnon is an informal pro-Donald Trump internet conspiracy group, whose followers believe that the US has been ruled by "deep state" criminal organisations including Hollywood stars and Satan-worshipping global elites.
The conspiracy theory is centred on the baseless belief that the president is waging a secret campaign against enemies in the "deep state" and have attacked and harassed his political opponents on social media.
Followers of the group have also claimed that the Democratic Party are engaged in international crime rings, including sex trafficking.
For more than two years supporters have tried to solve clues and intelligence they believe is being leaked by a high-level mole in the US government named "Q".
Does QAnon pose a threat?
The FBI issued a warning last year and said that "conspiracy theories like QAnon" could fuel "extremist violence" and designated the group a potential extremist threat.
In a statement posted on Twitter, the company said: "We've been clear that we will take strong enforcement action on behaviour that has the potential to lead to offline harm."
Mr Trump has retweeted QAnon-promoting accounts and its followers flock to his rallies wearing clothes and hats with QAnon symbols and slogans.
QAnon's content, which started on the fringe internet, has spread widely across mainstream social media platforms such as Facebook, TikTok, YouTube and Twitter and into the political arena.
Twitter’s move follows in the footsteps of Facebook, which in May also removed several groups, accounts and pages against QAnon.