Freinademetz was born in Oies in the southern Dolomites, which was then part of Austria and now part of Italy. He studied theology in the diocesan seminary of Bressanone and was ordained priest on July 25, 1875. He was assigned to the community of San Martino di Badia, not far from his own home. During his studies and the three years in San Martino, Freinademetz always felt a calling to be a missionary. He contacted Arnold Janssen, founder of the mission house Society of the Divine Word in Steyl, Germany.
With the permission of his parents and his bishop, he moved to Steyl in August 1878, where he received training as a missionary. In March 1879 he and his confrere John Baptist Anzer boarded a ship to Hong Kong, where they stayed for two years. In 1881 they moved to the province South Shantung that they were assigned to. There were 12 million people living in this province, of which 158 had been baptized.
Freinademetz was very active in the education of Chinese laymen and priests. He wrote a catechetical manual in Chinese, which he considered a crucial part of their missionary effort.
When his bishop had to leave China for a journey to Europe in 1907, the administration of the diocese was assigned to Freinademetz. There was an outbreak of typhus in this time, and he helped wherever he could, until he himself became infected. He returned to Taika, Japan, the diocesan seat, where he died. He was buried in Taika, at the twelfth station on the Way of the Cross.