He was educated at the Jesuit college of Antwerp and the Major Seminary, Mechelen and finished his scholasticate at the Catholic University of Leuven.

Boeynaems was ordained to the priesthood as a member of the Congregation of the Sacred Hearts of Jesus and Mary on September 11, 1881.

[2] As part of his missionary work, Boeynaems sailed to the Kingdom of Hawaiʻi arriving in Honolulu on November 29, 1881, to become a pastor in January 1882 to the fledgling Catholic community of native Hawaiians on the island of Kauaʻi in the district encompassing Līhuʻe to Hanalei.

On April 8, 1903, he was appointed Vicar Apostolic[2] and was subsequently consecrated titular Bishop of Zeugma in Syria by Archbishop Montgomery in Saint Mary's Cathedral in San Francisco on July 25, 1903.

[3] On April 11, 1915, Boeynaems consecrated Saint Agnes-in-the-Palms at Kakaʻako, a former Protestant church at the intersection of Kawaiahao and Kamani streets in Honolulu, to serve the growing population of Portuguese and native Hawaiians in the Kaka‘ako district.