The head of state was due to travel by helicopter to the event being staged in the grounds of the Palace of Holyroodhouse on Friday.
But a Buckingham Palace spokeswoman said: “Predicted weather conditions for the morning suggest travel disruption is likely and Her Majesty wishes to avoid any delay to the service.”
The spokeswoman added the Queen, who is Colonel-in-Chief of the regiment, sends her “best wishes” to the military unit on the occasion of its 50th anniversary.
The Duke of Kent, the regiment’s deputy Colonel-in-Chief, was due to accompany the Queen and will still attend the Drumhead service which will commemorate the formation of the Royal Scots Dragoon Guards in 1971.
The Royal Scots Dragoon Guards’ recent commitments include Operation Cabrit, the UK contribution to Nato’s Enhanced Forward Presence mission in Poland and the Baltic states.