It is believed that he is the first sitting MP to attend one of the controversial group’s events.
The Reclaim Australia movement advocates the closing down of mosques and Islamic schools and ending halal food certification in a bid to end radicalisation.
In a post on his Facebook page Mr Christensen wrote: "I want to support people who seek to defend our Australian way of life, our culture and our freedoms from the threat of radical Islam. I made the decision to speak after reviewing the Reclaim movement's 24 principles. “
In a post on the Reclaim Australia Mackay rally Facebook page Mr Christensen's attendance was warmly welcomed.
"WE HAVE SOME GREAT NEWS EVERYBODY................. GEORGE CHRISTENSEN WILL BE ATTENDING OUR RALLY HERE IN MACKAY AS A GUEST SPEAKER ON SUNDAY 19TH. THIS IS FANTASTIC FOR OUR CAUSE AND WE ARE VERY EXCITED TO HAVE HIM ATTEND OUR RALLY."
Mr Christensen also claimed there were attempts to stop his attendance at the rally.
“There are those who want to silence me and stop me from being at the rally. The left-wing Getup! website, community run, already has a petition on it trying to get the Prime Minister to stop me from attending this gathering of my local constituents,” he wrote on Facebook.
“Hell will freeze over before I give in to such intimidation. However, it's plain to see who wants to shut down free speech and the right to peaceful assembly and protest in this country.”
A spokeswoman for Prime Minister Tony Abbott's office responded to SBS' questions with a one line response: "This is a matter for Mr Christensen."
Mr Christensen has been outspoken on issues around Islam in the past, labelling the #illridewithyou hashtag as a 'pathetic' left wing campaign.
The social media campaign which sprang up in the midst of the Sydney cafe siege was critcised Mr Christensen as a "pathetic left wing campaign" that creates "false victims".
Reclaim Australia held a series of controversial rallies around the country in April decrying "sharia law, halal tax and Islamisation"and has been accused of spreading hate and racism. Reclaim has denied it is a racist group and describes its aims as patriotic.
Many of the flag-waving crowd-goers, in the hundreds, chanted "Aussie, Aussie, Aussie - Oi, Oi, Oi" and were carrying home-made banners denouncing sharia law.
The group appears to be loosely organised with reports of divisions and splinter groups breaking off, such as the United Patriots Front which is planning its own anti-Islam rally this weekend in Melbourne.
Comment has been sought from Reclaim Australia.
