The chain arrived in Glasgow in July, opening the largest Thai restaurant in Europe, over four floors in the listed Townhouse building on Buchanan Street.
That £2 million development followed openings in Leeds, Liverpool, Manchester, Sheffield and Birmingham since 2004.
The latest funding comes from Santander's Breakthrough programme which offers mezzanine finance at a low rate to help bridge the recognised gap in the market between angel and equity investment.
Chaophraya has secured £2.4m of growth capital to open in the Scottish capital, where it is currently advertising for a business manager to run a workforce of 30.
Martin Stead, chief executive, said: "We have been steadily growing our businesses since establishing our first restaurant eight years ago.
"Our aim is to take the Chao experience to as many cities as possible but we had reached a stage in our lifecycle where accessing further finance to invest had become problematic. Santander's growth capital investment enables us to borrow against our future success without having to give up a slice of the business.
"It's great to see a bank thinking outside the box to create something this innovative."
The Edinburgh outlet will open next month with the company also planning to expand its Leeds site and have a new restaurant at as an yet unnamed location at the start of next year.
It is only the fourth investment under Santander UK's programme and was announced by the Spanish bank's chief executive, Ana Botín, at an event at the University of Edinburgh to celebrate entrepreneurship and higher education.
The university signed a collaboration agreement with San-tander's global universities programme in 2007 involving £650,000 of funding for scholarships, travel grants and support for entrepreneurs and volunteers.
Ms Botin, who also gave a lecture to students at the university, said: "We have already increased lending to businesses in Scotland by 32% in the past year and we are providing £200m in growth capital to help UK companies invest in their businesses and take their growth to the next level."
Santander said it had provided £110m of new business loans in Scotland during the first six months of this year.
The bank has partnerships with eight Scottish universities – Queen Margaret, Edinburgh Napier, Glasgow Caledonian, Glasgow, Stirling, Strathclyde and St. Andrews – and provides £682,000 of funding each year.
Contextual targeting label: