David Johnston and his wife Sharon stood for a moment of silence in front of the memorial this morning after viewing the day's first posting of sentries at the Tomb of the Unknown Soldier.
Earlier today, Johnston met with Cpl. Ryan Button, who was on duty with Cirillo when the Oct. 22 shooting took place.
The governor general and his wife had just returned last night from visits to Poland, the Netherlands and Belgium.
While in Belgium on Tuesday, Johnston wrote a note of condolence for Cirillo as friends and family mourned his loss at a funeral in Hamilton, Ont.
The governor general, who is also commander-in-chief of Canada's armed forces, called last week's shooting at the National War Memorial and the attack on Parliament Hill a despicable act, and said he was humbled by those who answer the call to serve.