Mr Hunt will say farmers and fishermen “face uncertainty” with no deal, and as PM he would “help smooth it over”.
He will compare the help to the bail-out for banks in the financial crisis.
Meanwhile, plans by his rival, Boris Johnson, to give public sector workers a “fair” pay rise have been revealed.
Mr Johnson and Foreign Secretary Mr Hunt are competing against each other to become the next Conservative leader.
The Conservative Party’s 160,000 members will begin voting next week and Theresa May’s successor is expected to be announced on 23 July.
The UK is due to leave the EU on 31 October and a no-deal exit remains the default position in UK law after MPs rejected the agreement Theresa May agreed with Brussels three times.
Both men have vowed to go back to Brussels and negotiate a better deal with the EU – but both have also said they are prepared to leave without one if that cannot be done.
‘No deal relief’
If the UK does leave without a deal, it will automatically trade under the basic World Trade Organization (WTO) rules.
Under these rules, the tariffs – the taxes on imported and exported goods – will be different to what the UK currently trades under, which means the cost to farmers to export products could change or they could be affected by competition from abroad.
The National Farmers Union has said British farming will be “damaged” if that happens.
In a speech in London later, Mr Hunt will say that a government led by him would cover the costs of the tariffs that would be imposed on the exports of the farming and fishing industries.
He will promise to create a temporary “no deal relief programme” – designed to be similar to US President Donald Trump’s promise of £16bn for farmers affected by Chinese tariffs.
He will also promise to set up a no-deal committee to make sure the government is ready to leave by 31 October, as well as a transport committee to keep goods moving through ports and airports.
“If you’re a sheep farmer in Shropshire or a fishermen in Peterhead I have a simple message for you,” Mr Hunt is expected to say, “I know you face uncertainty if we have to leave the EU without a deal.
“I will mitigate the impact of a no-deal Brexit on you and step in to help smooth those short-term difficulties.
“If we could do it for the bankers in the financial crisis, we can do it for our fisherman, farmers and small businesses now.”
The money would come from what Mr Hunt calls a “no deal war chest” – cash the current Chancellor Philip Hammond has earmarked for a no-deal departure.
Mr Johnson also promised to support the rural community after Brexit during a meeting with farmers in Cumbria last week, insisting farmers “should be assured that we will support the rural community, with price support, efficiency payments, whatever”.
When challenged about the potential impact leaving the EU without a deal would have on exports, Mr Johnson said he did not want such an outcome and intended to negotiate a tariff free area with Europe.
Both leadership contenders have been unveiling a range of tax and spending plans designed to win support for their candidacies.
One of Mr Johnson’s leading backers, Health Secretary Matt Hancock, told the Times the days of public sector “pay freezes” under Theresa May and David Cameron would be over.
Mr Hancock said: “People in the public sector need to be properly rewarded for the brilliant job they do.”
Mr Johnson has vowed to cut taxes if he becomes prime minister, predicting this would stimulate the economy, and increase government revenues.
“Now that there’s money available, we need to show the public sector some love,” Mr Hancock said.
Mr Johnson has also said he would partly fund some of his plans from the so-called no deal “war chest”.
On Sunday, Mr Hunt said he would be prepared to pursue a no-deal Brexit “with a heavy heart”.
Mr Johnson has previously said the UK must leave on 31 October “deal or no deal” and that he would take the UK out of the EU by Halloween “come what may, do or die”.
In an interview with Sky’s Sophy Ridge on Sunday, Mr Johnson reiterated the commitment, saying he would take “personal responsibility” for ensuring the UK leaves by that date, with or without a deal, as the current “drift and dither” could not continue.
Mr Johnson has continued to refuse to face Mr Hunt in a head-to-head debate before ballot papers are sent out to the Tory membership.
A Sky News debate was planned for Monday but will now see Mr Hunt interviewed by Kay Burley.