Hannity is defending his on-stage appearance on the grounds that "this was not planned", even though he held a live show at the rally while the Trump Campaign made a point of highlighting his presence. When Fox found out in 2010 that the Tea Party had advertised that Hannity would be appearing at one of his fundraising rallies, Fox said it had not approved the arrangement and ordered him back to NY.
"I want to thank everybody for the way you behaved, that was beautiful" said the president, "hopefully she'll be ok". He then delivered an inventory of Trump's accomplishments, took a veiled swipe at former President Barack Obama, then left the stage. "I'm aghast as are a number of other people".
Hannity's role at the rally had been put in question by Trump campaign itself.
Trump's midterm efforts will not stop with his Missouri rally on Monday night.
She did not immediately add any clarification about how the network "addressed" the events, but Hannity tweeted soon after about his participation. The president urged supports to "pretend" he was on the ballot.
"They say we're divisive, but we're not divisive, we're defending an America that has strayed from its founding", he said. He described them as "livid".
"Fox News does not condone any talent participating in campaign events", the network said in a statement. "We have an extraordinary team of journalists helming our coverage tonight and we are extremely proud of their work".
Hope Hicks, chief communications officer for Fox - the soon-to-be parent company of Fox News - did not respond to a Tuesday morning email asking whether Rupert or Lachlan Murodch, the father and son who control Fox News, had any comment on or approved of Hannity's behavior.
As shameless as that kind of partisan cheerleading is for a channel with "news" in its title, I would not be writing this column if that was all Hannity and Fox News did Monday. Hannity himself had tweeted: "To be clear, I will not be on stage campaigning with the president".
"They do awesome work day in and day out in a fair and balanced way", he said on Twitter.
Hannity has for years flouted the usual standards required of Fox News employees.
Hannity, cable news' most popular personality and a vocal Trump defender, has twice been publicly rebuked by Fox for campaign activity. Hannity was made to cancel a 2010 appearance in Cincinnati when it was revealed it was to be a fundraiser for the Tea Party, and when he was featured in a 2016 Trump campaign video Fox told him was told never to do it again.
While Hannity has been able to get away with breaking normal protocol, the network had previously attempted to reign him in.
That has not been the case for Hannity however, who previously suffered no fallout when it was revealed he was a client of lawyer Michael Cohen, who at the time was also President Trump's legal advisor.
A Fox spokesperson denied giving Mr Hannity approval to speak at the rally.
He and first lady Melania Trump voted in NY via absentee ballot several weeks ago, the White House said.