Ms Say said the sister city relationship would serve as yet another testament to how Turkey and New Zealand had built a new friendship out of "the embers of a horrible war".
"All the fallen in Gallipoli are all our grandfathers, and we are proof for posterity that people who once fought as enemies can proudly stand shoulder to shoulder today in remembrance of their grandfathers' sacrifice, and in celebration of their friendship."
Ms Say said when Governor-General Sir Jerry Mateparae visited Turkey in April 2014, discussions took place with Governor of Canakkale, Ahmet Cinar, over the establishment of the sister city relationship.
Earlier this month, Mr Cinar assured New Zealanders travelling to Gallipoli that they would be safe from terrorism at centenary commemorations.
He said Canakkale was one of the most "secure places in the world".
Authorities in the area had experience from previous years, and similar security measures would be in place at centenary celebrations, he said.
"Security-wise, all kinds of precautions, all kind of measures have been taken," he said. "There won't be any risk."
Following the announcement, the Wellington City Council will sign a memorandum of understanding with the Canakkale Municipality, to formalise the relationship.