Soldiers gave the Queen a guard of honour and The Pipes and Drums of the regiment's 3rd Battalion performed during the ceremony.
The Royal Regiment of Scotland's mascot, Shetland Pony Lance Corporal Cruachan IV, also took part.
The welcome ceremony was not performed last year due to the coronavirus pandemic and the Queen took part in her role as Colonel-in-Chief of the Royal Regiment of Scotland.
Watch: 5 SCOTS welcomed the Queen to Scotland earlier this summer during the Ceremony of the Keys.
The Queen traditionally inspects troops when she takes up residence at the castle and, outside the gates, she cast her eye over soldiers from Balaklava Company, 5th Battalion the Royal Regiment of Scotland.
The monarch's annual stay at Balmoral is the first time she has holidayed on her private estate since the death of her husband, Prince Philip.
A picture released following Philip's death in April showed the Queen and her late husband surrounded by their great-grandchildren at their Scottish home.
The Queen left for Scotland just over two weeks ago and is believed to have been staying at Craigowan Lodge on the Balmoral estate – where she normally spends the initial period of her summer holiday.
She is unlikely to be alone for long as serving members of her family are invited to spend time with her at the castle every summer.
Cover image: Queen inspecting troops from Balaklava Company, 5th Battalion the Royal Regiment of Scotland, at the gates of Balmoral Castle.