The new venture, isleHoliday.com, has been set up by community interest company Isle Develop, which is based on the Isle of Tiree.
It is billed as a community-focused alternative to the popular AirBnB accommodation site and a means of raising funds for affordable housing and long-term rental properties.
The aim behind the initiative is to ensure that more revenue generated by tourism in the islands stays in local communities.
Edinburgh fire: Blaze breaks out at Franco's fish and chip shop in Newington
Edinburgh crime news: Teenage boy arrested after riding motorbike in a 'dangerous manner in a public place'
Edinburgh fire: ‘I knew I had to just get out’: Residents evacuated as fire breaks out in Newington area of Edinburgh
Ladies Day at Musselburgh Races: Children's nurse crowned most stylish woman
Crime: Teenage thug who fathered a child during sentence is back behind bars
Like AirBnB, isleHoliday will charge commission on every booking taken – 12 per cent as standard, or 10 per cent for properties owned by islanders.
Payments will go towards running the business – which already supports two island jobs – but all surplus will go into the Isle Develop fund.
That fund will focus on supporting small businesses, community schemes and housing projects across the Scottish islands.
The founders say they want to make sure the islands remain great places to live and work as well as great places to visit.
Rhoda Meek, founder of Isle Develop, said, “The housing problems caused by the short-term letting market in the islands are well documented.
“It will take time to change that situation and involve action at a local and national government level.
“But in the meantime, the letting market exists.
“Our goal is to use it to generate revenue which can be used to the benefit of our communities - particularly in relation to affordable housing and long-term rental options for residents.”
Holidaymakers using the portal will also benefit from local knowledge.
“We know our Bernerays from our Burras,” said Ms Meek.
“By working together with accommodation providers and local organisations we can offer rich information about island life before visitors arrive - from driving on single-track roads to public facilities, events and great local businesses to visit during their stay.”
She added: “We want to put faces to places and start to change the narrative from destination first, to community first.”
The new platform is the second for Isle Develop.
It also runs the island shopping site isle20.com, which features a wide range of locally made products and gifts – from jewellery to gin and artworks to knitwear – from 31 Scottish islands.
Scotland has around 800 islands, most of which are found in Shetland, Orkney, the Inner Hebrides and Outer Hebrides.
But many locals face major obstacles in finding a permanent residence due to a shortage of houses and land, high levels of second homes and rocketing property prices.
Recent figures suggest 40 per cent of housing stock on both Tiree, in the Inner Hebrides, and West Harris, in the Western Isles, are holiday homes.
On the Isle of Skye around 10 per cent of properties are second homes – ten times the rate across Scotland.
Affordable properties for young islanders has been a long-running problem, but has worsened since the outbreak of Covid-19 due to an influx of people relocating from elsewhere with more cash to spend.