The Queen will officially open the fifth Assembly at the Senedd today, ahead of her 90th birthday celebrations at the weekend.
Presiding Officer Elin Jones, Her Majesty and the First Minister Carwyn Jones will all make speeches for the opening of the new Assembly.
The Queen will be accompanied by The Duke of Edinburgh, The Prince of Wales, and The Duchess of Cornwall.
A 21-gun salute will be fired at Cardiff Pierhead when the royal train arrives at Cardiff Central Station.
The Welsh and UK National anthems will be played and a royal salute given as the Queen reaches the main entrance to the Senedd building.
A guard of honour will be in position in front of the Senedd, where the Queen will proceed through Y Nueadd to the Siambr.
The formal opening ceremony will include a performance by the National Youth Choir of Wales and a student will read a specially commissioned poem.
The Queen and the Duke of Edinburgh will also open Cardiff University's state of the art Brain Research Imaging Centre. The £44million centre will look into the causes of conditions such as dementia, schizophrenia and multiple sclerosis.
Speaking ahead of the visit, Vice-Chancellor Professor Colin Riordan said he was delighted to welcome the royal visitors.
"It's an honour for the University and highlights the significance of the outstanding facilities here, including a specially adapted MRI scanner found in only one other location in the world," Prof Riordan said.
"Our work is of global importance as we seek to provide insights into brain disorders that will lead to the development of better treatments."