David Kerfoot, who chairs the York and North Yorkshire Local Enterprise Partnership, said supporting local businesses "is not only going to be important for us now, it's going to be important for us for a considerable length of time".
He spoke at a press conference organised by the North Yorkshire Local Resilience Forum made up of health, council, social care and police leaders in England's largest county.
Mr Kerfoot outlined the support made available to businesses by Chancellor Rishi Sunak which includes the furlough scheme, discretionary funds being administered through local authorities and a loan scheme which has been extended until the end of March.
But he said: "Now's the time for people to be local, shop local and buy local, never before in our history have we needed local supply chains, as we do need now.
"Please try and support your businesses in your local communities, and on your local high streets. Many more businesses now are actually equipped to sell online. And they're prepared to sell online for click and collect takeaway.
"So I urge you to take up the cudgel and support. It's very easy to set up and many businesses have already taken that up to be able to actually connect online with their clients.
"Shop local is not only going to be important for us now, it's going to be important for us for a considerable length of time."
Mr Kerfoot said the restrictions would impact on North Yorkshire, particularly on hospitality, leisure and the visitor economy, "in quite a big way".
He said: "It's interesting that 97 per cent of our economy is actually small and medium-sized enterprises (SMEs). They are the backbone of what we do across our patch, and I'm afraid that there will be ultimately some casualties, as there already has been.
"But it's our job as a LEP to be positive, and to help those businesses as much as we can, through this very very difficult situation."
Businesses in York and North Yorkshire can find out more about the support available at www.ynygrowthhub.com.