Leon Thompson, of the industry body UKHospitality Scotland, said there were a “lot of concerns” in the sector about the financial impact of industrial action.
He spoke out as the RMT union confirmed next week’s strikes will go ahead after talks failed to resolve a row over pay, jobs and conditions.
Network Rail staff across the UK, such as signal operators, will strike on Tuesday, Thursday and Saturday – with ScotRail already having warned it will only be able to operate a limited service on five routes.
Those are all in the central belt, with the action leaving vast parts of Scotland without any train services at all.
Bosses at the Moor of Rannoch hotel and restaurant in Highland Perthshire tweeted that they had suffered “mass cancellations” because of the RMT action.
With 70 per cent of its customers travelling by train to the remote beauty spot, they said they had “lost almost all of our bookings” for the week.
Mr Thompson said there was a “lot of concern in the sector right now about the financial impact” the strikes will have.
He told BBC Radio Scotland’s Good Morning Scotland programme that businesses such as bars, restaurants and hotels were “still living with the financial shadow of Covid” and had been “grappling” with the lack of late-night train services in Scotland as a result of the temporary timetable brought in following a separate dispute with train drivers.
Mr Thompson said: “I have got member businesses saying they are already taking cancellations, hotels are saying people are cancelling their trips, cancelling their stays – even for this weekend – because of the disruption next week.
“There is a lot of concern in the sector right now about the financial impact this is already having and will continue to have when we get to next week.”
He continued: “Businesses are still living with the financial shadow of Covid.
"They desperately need to trade and be able to trade at their optimum level.
"They are experiencing rising costs on their utilities and across the board with supplies as well.
“It is absolutely imperative they are able to trade at full capacity in order to keep going.
“A lot of visitors use the train to travel around, and any disruption just puts people off and they are just going to change their plans.”
He added that after “two years of lockdowns and restricted trading” this has been “the first full summer businesses will have had to be open and welcome businesses and guests”.
“Having industrial action on our railways is really just going to hold our businesses back,” he said.
RMT general secretary Mick Lynch said that “despite the best efforts of our negotiators no viable settlements to the disputes have been created” in talks with Network Rail.
As a result Mr Lynch said: “We are confirming that the strike action scheduled to take place on 21, 23 and 25 June will go ahead.”