Joseph Marie Garavel was born probably in 1823 or 1824 in Balmont Jarvose, near Chambéry in Savoy, while it was still part of the Kingdom of Sardinia. He trained for the priesthood in Paris and was ordained deacon. During this time he met Bishop J. B. F. Pompallier, then recruiting clergy for the new diocese of Auckland. Garavel sailed with him to Auckland on the Océanie and landed on 9 April 1850. He had learnt some Maori on the voyage, and having been ordained priest on 27 April, he immediately began work at Rangiaowhia, where he continued successfully the work begun by the Marist Father Pezant. The immediate care of the Rangiaowhia mission was handed over to Michael O'Hara in 1859, when Garavel became vicar forane (overseer) for the Maori missions and for the Fencible settlements near Auckland. He also served as secretary of the diocese during Pompallier's absence in Europe in 1859–60.
Between 1850 and the war in Waikato in 1863–64 Garavel built up the central Catholic mission at Rangiaowhia by the addition of a large, permanent church, and a school for the Maori which attracted generous help from the central government. Rangiaowhia was a prosperous area, owing to the good work of John Morgan and local Maori in introducing European agriculture, particularly wheatgrowing. But Garavel's mission covered the Waikato, Waipa and Mokau regions and he travelled extensively, gaining the trust of the Maori to an extent probably unequalled by any other missionary. It was in his house that Governor Thomas Gore Browne met the leaders of the King movement in 1857.
Garavel's last two years in New Zealand were dogged by controversy. In 1862 he became involved in a disagreement with Pompallier. Garavel had been asked by Bishop P. J. Viard of Wellington to comment on accusations concerning Pompallier's administration of the diocese of Auckland. Garavel upheld two of the complaints – that Pompallier was a poor financial administrator, and that he had failed to carry out his episcopal visitation of the parishes. Viard apparently told Pompallier what Garavel had said, for Garavel came to believe that the bishop was persecuting him. In March 1863 Garavel requested a transfer to another parish. The request was refused.
When war broke out in 1863 Garavel was still able, most of the time, to move freely in Maori districts and to pass from one side to the other, carrying out his spiritual ministrations and giving information to both parties. His impartiality caused some Europeans to see him as disloyal. On Christmas Day 1863 Garavel arrived at Opotiki to convey Pompallier's attitude to the war to the Bay of Plenty tribes. He also carried a letter from Wiremu Tamihana Tarapipipi, the contents of which led to an outbreak of fighting. The CMS missionary Carl Völkner consequently accused him of disloyalty; called to Auckland by Governor George Grey, Garavel was questioned but allowed to return to Opotiki. He later denied any knowledge of the contents of the letter.
Garavel's departure for Sydney on 1 August 1864 may have been due to government pressure as a result of the Völkner incident, but the likelier reasons were the disagreement with Bishop Pompallier and his own realisation that the great experiment of the Christian Maori agricultural villages of Kihikihi and Rangiaowhia had been brought to an abrupt end.
Garavel was highly praised for his work in the archdiocese of Sydney. He was obviously a capable, intelligent, dedicated man and a good organiser. When he visited New Zealand again in 1882 he was warmly received by Maori and European alike. His best work was done among the Maori people and it is a pity that the war prevented its bearing full fruit. He died at Petersham, Sydney, Australia, on 9 October 1885.