Earlier this week, Ms Hopkins, a Donald Trump supporter, revealed she had “booked her flight” for her appearance on the show.
The announcement sparked a social media campaign urging viewers to submit complaints to RTÉ.
Complainants cited Ms Hopkins’s views on refugees, minorities, and other issues as reasons why the broadcaster should not afford her a platform.
A spokesperson for RTÉ last night revealed that the broadcaster had received 641 emails critical of Ms Hopkins’s planned appearance.
“Donald Trump’s victory has been one of the biggest political upsets of our time,” RTÉ said in a statement.
“Donald Trump himself expressed many controversial views during the campaign and is now president elect.
“Katie Hopkins is one of his most vocal supporters in the UK. She’ll be giving her take on why his message resonated with American voters, and her promise to move to America in the event of a Trump victory.
“The American election and its aftermath has been and will continue to be covered extensively across of range of RTÉ’s output,” said the statement.
Advance publicity for tonight’s programme described Ms Hopkins as a “Trump cheerleader”.
An RTÉ press release announced: “Still celebrating the election of Donald Trump, controversial newspaper columnist and broadcaster Katie Hopkins joins Ryan to talk about her promise to move to America in the event of a Trump victory as well as her gloating claim that ‘Trump has crushed the leftie luvvies’.”
Previous Late Late Show guests were among those who questioned Ms Hopkins’s planned appearance on the programme.
Oscar-nominated filmmaker Lenny Abrahamson, broadcaster Maia Dunphy, and musicians James Vincent McMorrow and Josh McClory all took to Twitter to voice their concerns.
“Never watch @RTÉLateLate Show as a matter of taste. Now I’ll avoid as a matter of principle. Professional bigot Katie Hopkins is on,” said Mr Abrahamson.
Never watch @RTELateLateShow as a matter of taste. Now I'll avoid as a matter of principle. Professional bigot Katie Hopkins is on.— lenny abrahamson (@lennyabrahamson) November 9, 2016
“Very disappointed to hear the #LateLateShow is giving shit- stirring dullard Katie Hopkins a platform for her frankly tiresome bigotry,” Ms Dunphy tweeted.
Very disappointed to hear the #LateLateShow is giving shit-stirring dullard Katie Hopkins a platform for her frankly tiresome bigotry. 😞— Maïa Dunphy (@MaiaDunphy) November 9, 2016
Mr McMorrow said he hoped Ms Hopkins would be asked tough questions rather than treating her like “a whimsical character”.
If @RTELateLateShow is havin Katie Hopkins on I hope they ask her tough questions rather than treatin her like a whimsical "character"— James Vincent McMorrow (@jamesvmcmorrow) November 9, 2016
This isn't a game show these are real people throwin rhetoric 2A base that's listenin, hope u guys step up & challenge that @RTELateLateShow— James Vincent McMorrow (@jamesvmcmorrow) November 9, 2016
“Katie Hopkins shouldn’t be given any air time whatsoever, can’t understand the @RTÉLateLateShow at all,” Mr McClory, guitarist with The Strypes, said.
Katie Hopkins shouldn't be given any air time whatsoever, can't understand the @RTELateLateShow at all.— Josh_McClorey (@Josh_McClorey) November 10, 2016