The breakthrough rail link, which will save passengers from changing at Glasgow Central, will also stop at Newton-on-Ayr and Barassie
Ayr MSP John Scott said: "I welcome any improvement on the service between Ayr and Edinburgh. In the past I have grown used to walking between Glasgow Central and Queen Street - although not a great distance, it is an inconvenience.
"This new service will take the inconvenience out of travelling from Ayr to Edinburgh and make life much easier."
The coast to coast link will pass through Glasgow Central via Carstairs to the capital as part of a new ScotRail summer timetable offering more services.
The new direct service is due to start on May 19.
Ayr Advertiser Facebook followers have said a new direct link to the east coast would be very welcome.
Elaine Kidd posted on the Advertiser page: " It would be great for those looking to commute to Edinburgh for a job, as well as possibly boost tourists numbers for Prestwick Airport."