The SDLP leader has said that she will wear a poppy while attending a Remembrance Sunday ceremony this weekend.
It is understood that Margaret Ritchie will be the first leader of a nationalist party to wear a poppy.
She said that she hoped it would be seen as a gesture of "reconciliation and reaching out".
The poppy has been a controversial symbol in Northern Ireland, often dividing unionists and nationalists.
It is sold by the British Legion in the run-up to Remembrance Sunday in November to raise money for veterans.
Ms Ritchie said: "It doesn't mean that I agree with those wars - in fact, I would be totally opposed and I would agree with Wilfred Owen who wrote about the futility of war.
"But people lost their lives and we have to show some element of respect and remembrance, and that is what I am doing."
Sinn Fein's Alex Maskey broke ground in 2002 when as his party's first Lord Mayor, he laid a wreath to remember those who fell at the Battle of the Somme.