In a social media post confirming Mr Bongino's appointment, Mr Trump wrote: "Dan Bongino, a man of incredible love and passion for our Country, has just been named the next DEPUTY DIRECTOR OF THE FBI, by the man who will be the best ever Director, Kash Patel.
Mr Bongino reacted in a podcast episode, saying: "If the video has been sitting in the FBI evidence locker for four years now, it's almost like someone in the FBI knows the identity of this bomber and that Trump is going to find out.".
Responding to the post on X, where Mr Bongino has some 6.6 million followers, the incoming deputy FBI director thanked the president, along with Ms Bondi and Mr Patel.
During an interview last year, Mr Bongino urged Mr Trump to commit to forming a commission to reform the Secret Service, calling it a "failed" agency and criticising it for the two assassination attempts aimed at him last year.
The FBI Agents Association, a non-profit organisation aimed at supporting current and retired agents, has not commented on Mr Bongino's appointment, but has created a memo seen by NBC News that appeared to suggest he was not qualified for the position.