After testing positive for Covid the 95-year-old Queen had to cancel a number of events last week, but is now well enough to return to her meetings.
The events were virtual audiences with ambassadors of Andorra and Chad.
Palace aides say the Queen will also be taking part in some private engagements.
Although Buckingham Palace officials are not giving a “running commentary” on the Queen’s health, sources suggest that the return to carrying out engagements shows a recovery from Covid symptoms.
The virtual audiences were carried out by video link from Windsor Castle.
The Queen tested positive for Covid on 20 February and cancelled planned events after she suffered from mild, “cold-like” symptoms.
She had been caught in a wider Covid outbreak in Windsor Castle, where she lives and has stayed while recovering.
Although unable to take part in on-screen meetings, the Queen had been said to be carrying out “light duties”, such as reading state papers.
There had been plans for an in-person appearance this week, at a diplomatic reception in Windsor Castle, but that has been cancelled by the Foreign Office.