Members of the public will be able to dial 111 to receive medical help and advice.
The government said callers north of the border would no longer be charged for calling NHS 24 from a landline or mobile.
Health Secretary Alex Neil was due to officially launch the "easy to remember" number in Edinburgh this morning, while meeting with patients who have benefitted from NHS 24. The service handles about 1.5 million calls every year.
It had previously been hoped that a new £27 million IT system, designed to improve the service patients got from NHS 24, would have been up and running by the time that the new number was in place. However, it emerged earlier this month that its implementation had been delayed indefinitely after issues emerged during testing.