The 19th-century religious figure is the first English person since 1976 to be canonised.
Newman led the Oxford Movement which promoted the idea that the Anglican Church should reconnect with its Catholic roots.
He was created a cardinal by Pope Leo XIII in recognition of his services to the cause of the Catholic Church in England.
50,000 people attended the celebrations in St Peter’s Square at which The Prince of Wales represented the UK.
After the service The Prince attended a reception at Pontificio Collegio Urbano, where Newman studied for the priesthood from 1846 to 1847.
In his speech at the reception, His Royal Highness spoke of Newman’s relevance today, saying:
He was able to advocate without accusation, disagree without disrespect and, perhaps most of all, to see differences as places of encounter rather than exclusion. These are principles that continue to inspire, and to guide each new generation.