Cheers were heard from onlookers as Prince William and Princess Catherine led their children into the chapel.
As they walked, Princess Charlotte waved to the crowds of people behind barriers watching on.
Princess Anne joined, accompanied by husband Sir Tim Laurence, as well as Prince Edward and his family.
The King and Queen arrived last and one onlooker was heard shouting “God bless the King”.
The service is seen as a traditional family event as opposed to an official engagement.
The King did not issue an Easter message this year.
On Thursday, the King and Queen attended the traditional Maundy service at Denbighshire in Wales.
That event commemorates the Last Supper and the importance of humility and service to others.
The King presented gifts to 77 men and 77 women from the UK in recognition of outstanding Christian service and for helping people in their communities.