The ongoing impact of three months of lockdowns had reduced the ability of too many families to provide the necessities of life and get through Christmas, Williams said.
"We want to do something about it."
"Farmers Feed Families" encourages farmers and growers to consider donating via a Givealittle page which links directly to the Auckland Mission.
The target is to raise $100,000 - or the equivalent of about 800 boxes of food, which will each include a Christmas dinner.
"At a time when our farmers are getting okay prices, we are doing what we can, when others cannot," Williams said.
Federated Farmers NZ president Andrew Hoggard said the organisation was pleased to actively support the Mission's Zero Hunger initiative.
"Sometimes Feds does things that are not about politics or regulations. We just want to feed families, especially when times are tough. 'Farmers Feed Families', that's what we do.
"We often talk of how we can make connections between farmers and urban communities, well here's how."
Auckland City Mission was chosen as the recipient because it was able to get to those who need the support most - and fast.
More people had been turning to the Mission for support than ever before during this latest lockdown, and it would be difficult Christmas for many, the Mission's chief executive Helen Robinson said.
"Supporting people in Auckland who are facing the greatest need is a very real way farmers can connect in with the city where the majority of their produce and meat is consumed."
This year the mission supported more people than ever before through providing food, Robinson said.
"In one particular week, about 2000 parcels of food were distributed, which is more than four times the weekly amount prior to Covid-19.
"Quite simply we cannot do that without the generosity of people."
Having farmers show their support "in such a wonderful way" was incredibly helpful, Robinson said.
"Particularly as Christmas is fast approaching, which is the busiest time of the year. My thanks goes to them all."
The Mission expects to give out around 9000 Christmas food parcels and tens of thousands of gifts to families who will otherwise go without.