Two sets of brothers working in beef and retail respectively have driven their firms into a UK-wide top 100.
Red meat giant Dunbia, based in Dungannon, and Spar franchise owner Henderson's, based in Newtownabbey, are listed among the biggest contributors to regional economies in the UK.
Together, their businesses employ 5,800 people and have combined sales of £1.4bn and profits of £44m - according to the Sunday Times HSBC Top Track 100 league table, which lists Britain's top 100 companies with the biggest sales.
Dunbia is Northern Ireland's highest-placed company at number 76. It reported a 6% rise in sales to £764m.
The firm is led by managing directors Jack and Jim Dobson, who also founded the company, while Jack's son Stuart Dobson is also behind offal specialist Elmgrove Foods.
The Henderson Group is led by brothers Martin and Geoffrey Agnew, and it supplies Northern Ireland's Spar, Eurospar, Vivo and Vivoxtra franchises. It also operates nearly 80 stores of its own.
The brothers oversaw sales of £651m and in January announced a £10m revamp of their Co Antrim headquarters.
Henderson Group and Dunbia are on the list alongside UK household names such as shoe retailer Clarks, airline Virgin Atlantic and vacuum cleaner makers Dyson.
Dan Howlett, head of corporate banking in the UK at HSBC, said: "It's encouraging to see dynamic private companies from across the UK recognised by the Top Track 100 league table. These businesses are passionate and dedicated, which is evident across the different sectors, and they play an important part in helping to strengthen the British economy."
Dunbia's Jack Dobson has also been nominated for the title of EY Entrepreneur of the Year in Ireland, following in the footsteps of son Stuart, who was nominated last year. In March, the firm announced it would be creating 209 new jobs.