Prime Minister Stephen Harper, who invited Poroshenko to visit as a show of support for Ukraine as it fights pro-Russian rebels, will also meet with the president privately.
The visit comes after the Canadian government expanded its sanctions against Russia and revealed plans to send 300 observers to monitor Ukraine's parliamentary elections next month.
Poroshenko isn't the only foreign dignitary in town — the Governor General will be welcoming Crown Prince Frederik and Crown Princess Mary of Denmark at Rideau Hall this morning.
Elsewhere on and off Parliament Hill:
— the Conservative, NDP and Liberal party caucuses hold their weekly meetings to plot for the weeks ahead;
— The parliamentary budget officer is set to release a report on the prospect of tolls on Montreal's Champlain Bridge;
— The Canadian Radio and Telecommunications Commissions continues its hearings on the future of television in Canada.