John Roberts, OSB (1577 – 10 December 1610) was a Welsh Benedictine monk and priest, and was the first prior of St. Gregory's, Douai, France (now Downside Abbey).

[1][2] Roberts was baptised into the Anglican faith inside the local parish church of St Madryn but is said to have received his early education from an elderly man who had been a Cistercian monk at Cymer Abbey just outside Dolgellau until its dissolution by Henry VIII in 1537.

He moved on to Spain and joined St Benedict's Monastery, Valladolid, and became a member of this community in 1598,[3] where he was known as Brother John of Merioneth in reference to his birthplace.

Although observed by a Government spy, Roberts and his companions succeeded in entering the country in April 1603, where he was appointed vicar of the English monks of the Spanish Congregation on the Mission.

[5] This time he was absent for some fourteen months, nearly all of which he spent at Douai (now in northern France) where he founded and became the first prior of a house for the English Benedictine monks who had entered various Spanish monasteries.

He was captured again on 2 December 1610; the arresting men arrived just as he was finishing saying Mass in a house, having been followed by former priest turned spy John Cecil, who had compiled a dossier on Roberts for James I.

[5] It was usual for the prisoner to be disembowelled while still alive, but he was very popular among the poor of London because of the kindness he had shown them during the plague and the large crowd which gathered at his execution would not allow this.

Roman Catholic Bishop Edwin Regan said: "Although the name St John Roberts isn't as well known today, he is a major figure in our religious history."

[8] On 17 July 2010, Metropolitan Seraphim of Glastonbury of the British Orthodox Church, accompanied by Deacon Theodore de Quincey, attended an Ecumenical Service at Westminster Cathedral in celebration of the 400th anniversary of the Martyrdom of John Roberts.