Brian Docherty, chairman of the Scottish Police Federation, said he finds it unbelievable such a decision was taken.
Mr Docherty cited recent demonstrations in Belfast and the requirement for officers drafted in from elsewhere in the UK to be trained in the practices of the Police Service of Northern Ireland (PSNI).
He said: "I find it strange Northern Ireland was chosen as a venue, given the amount of pressure and the working conditions that the PSNI is under just now.
"Officers are under threat every day. It is a whole different form of policing from that we know.
"To enter the G8 into that mix, I find it unbelievable. I find it strange that they would do that."
It has been suggested that 4000 officers from England, Wales and Scotland will be needed as world leaders fly in for the meeting in June.
US president Barack Obama, Russian president Vladimir Putin, German chancellor Angela Merkel and others will gather at the summit at Lough Erne golf resort in Co Fermanagh.
It will be the first time the annual summit has been held in the UK since Gleneagles in Scotland in 2005.
Violent protests were seen in Belfast earlier this year over the decision to restrict the flying of the Union flag at City Hall. Dozens of police were hurt in the demonstrations.
Mr Docherty joined Strathclyde Police 20 years ago and was appointed chairman of the federation in February last year.
The Glasgow-based Scottish Police Federation negotiates pay, conditions and pensions for its 16,500 members. The chairman said: "I think that under the circumstances it would've been better planning to hold it elsewhere in the UK."
A spokesman for the Association of Chief Police Officers in Scotland said: "We are working with police colleagues across the United Kingdom to assess the policing needs surrounding the G8 summit in County Fermanagh later this year.
"It is anticipated that officers from Scotland will form part of the policing response and details are being discussed at the present time."