Nicola Sturgeon joined Health Secretary Jeane Freeman, patients and NHS employees to celebrate the occasion at the Royal Hospital for Children in Glasgow.
Ms Sturgeon used the anniversary to reassert a commitment to the health service being free at the point of need.
She said: “It was a pleasure to be able to celebrate this special birthday at the Royal Hospital for Children, with the patients and staff who make the health service the treasured institution that it is.
“Our NHS has gone from strength to strength over the past 70 years, and this anniversary is an opportunity to appreciate the vital role the service plays in all our lives.
“It is also a time to reaffirm our commitment to the founding principles of the NHS - that healthcare should be provided free at the point of need.
“This commitment remains as strong as ever, and is just as relevant today as it was in 1948, which is why we are investing record-high real terms health funding and have delivered an all-time high in NHS staff numbers.
“I’d like to take this opportunity to thank everyone who has contributed to the health service over the last 70 years, and all those who continue to work and volunteer across the NHS today.”
Ms Freeman said: “Since 1948 the NHS has delivered huge medical advances and improvements to public health, letting many more of us live longer, healthier lives.
“The NHS has all but eradicated diseases such as polio and diphtheria, and Scotland itself has a long and proud history of delivering medical advances, such as the establishment of ultrasound, the UK’s first successful kidney transplant and advances in the use of keyhole surgery.”
John Brown, chairman of NHS Greater Glasgow and Clyde, added: “It’s been an amazing 70 years for the NHS.
“Over the past few weeks, all across Scotland, there have been many events to mark the occasion and none more so than across Greater Glasgow and Clyde, where many of the events taking place have looked back at the history of the NHS, its innovations and its accomplishments over the last seven decades.
“Whilst it is only right that that we acknowledge and commemorate our past, it’s possibly even more important to look ahead to the future of our NHS and our young staff, just at the start of their careers, who will play an important role and make a significant contribution to the NHS for the next generation.”