Figures show the total amount paid to private taxi and hire vehicle services for replacing a cancelled rail service between April and September 2022 was £137,309.91.
The single most expensive journey was a fare from Wick to Inverness calling at all stops in between. The cost of this was £798.30.
The figures were revealed following a freedom of information request by the Scottish Liberal Democrats.
The party’s transport spokeswoman Jill Reilly said: “This is an astonishing sum of money for newly nationalised ScotRail to have shelled out in just six months. Even worse, it comes hot on the heels of the news that the service has racked up more than £400,000 in payments to rail users for delays.
“This is money that should be available for cutting fares and updating trains, carriages and stations.”
Phil Campbell, ScotRail’s head of customer operations, said: “We are absolutely committed to providing the best possible service for our customers. We know how much of an inconvenience it is to customers when things don’t go to plan, and we have an obligation to help people get to where they need to be when that happens.
“The use of taxis as alternative transport is a measure of last resort which we only use when we are unable to get people to their destination by rail, replacement bus, or through ticket acceptance on other public transport.”