One of the three tweets, which Trump retweeted Wednesday morning, includes video with the caption "Islamist mob pushes teenage boy off roof and beats him to death!" while another reads, "Muslim Destroys a Statue of Virgin Mary!"
Another video claims to show a "Muslim migrant" beating up a "Dutch boy on crutches."
The videos have been called inflammatory and Islamophobic.
As the deputy leader of Britain First, Jayda Fransen has been arrested on a number of occasions.
This year, she was arrested for using "threatening, abusive or insulting words or behavior" during a speech in August. Last year, Fransen was arrested and found guilty for religiously aggravated harassment after she hurled insults at a Muslim woman wearing a hijab.
Britain First was formed in 2011 by former members of the British National Party.
Fransen responded to Trump's retweets on Twitter, writing in all caps: "Donald Trump himself has retweeted these videos and has around 44 million followers! God bless you Trump! God bless America!"
Britain First's mission statement states that "Christianity in Britain is under ferocious assault" and that "Britain First has a proven track record of opposing Islamic militants and hate preachers and this fightback will continue."
"We want Islam banned in the UK," Fransen said in an interview in March with Australian Broadcasting Corporation. "We don't see why we should have to implement sharia law and sharia courts and have people wearing burkas, Islamic schools, mosques everywhere in our Christian country."
As a presidential candidate, Trump had said he believes "Islam hates us."
"There's a tremendous hatred. We have to get to the bottom of it. There is an unbelievable hatred of us," Trump said in a March 2016 interview with CNN.
Send a breaking news alert
Report a correction or typo
Learn more about the 6abc apps