CBCNews.ca is carrying his speech live.
As he did last year, Baird is making Canada's appearance at the world body's opening session.
Prime Minister Stephen Harper was in New York last week for a panel on child maternal health. He has addressed the General Assembly twice, most recently in 2010, and has faced criticism from the NDP and academics and former diplomats for not giving the address himself.
Harper has countered that Canada's prime minister has not traditionally appeared at the assembly year year.
Baird was at a UN event last week during the first week of the opening session, and spoke against the forced marriage of young girls.