Hur Libertas "H. L." Mackenzie (22 February 1833 – 26 December 1899) was a leading Scottish medical missionary and minister for the Presbyterian Church of England who was revered by the church for his nearly four decades of service to their mission at Shantou. During his tenure at the mission he made numerous lasting contributions such as his translation of the scriptures into the local Swatow dialect, ensuring the accessibility of important religious works, and establishment of out-stations that greatly expanded the mission's reach. Outside of Shantou, Mackenzie founded the Taiwan Mission on behalf of the Presbyterian Church and was invited to speak at missionary conferences in an array of cities that included Philadelphia, Shanghai, and Bristol.

Mackenzie was born in Inverness, Inverness-shire, Scotland on 22 February 1833. He was also christened in Inverness soon thereafter on 13 March 1833. Mackenzie was the fourteenth youngest of the seventeen children of Thomas Mackenzie and Grace Fraser. Mackenzie graduated from The University and King's College of Aberdeen, which has been merged into what is now known simply as the University of Aberdeen, with a Master of Arts (MA) degree in March 1854. He subsequently received his postgraduate theological training at New College in the University of Edinburgh, where he received his degree as a Doctor of Divinity (DD).

Mackenzie married his wife, Mary Bailie, in 1871 in London’s Marylebone neighborhood. Bailie joined him in Shantou in 1872. She made numerous contributions to the mission that complemented her husband's work, such as her important role in the construction of a boarding school for girls in 1873. Additionally, Bailie often accompanied her husband in his day-to-day missionary functions.

Mackenzie had two sons and two daughters: Theodore Charles Mackenzie, Thomas Alexander Mackenzie, Mary Lina Mackenzie, and Grace Margaret Mackenzie. Theodore, Mary, and Grace lived in Scotland and were visited by their parents in 1879, when Mackenzie and his wife were granted a furlough in Scotland. Thomas, the youngest, was born in China and remained with his parents in Shantou.

Mackenzie arrived at the Presbyterian Church of England’s foreign mission in Shantou in 1860 and aided in the construction of the mission’s main hospital, which was completed in 1863. The mission would eventually be expanded to contain a smaller hospital for overflow and a hospital designated for women, in addition to the main hospital. Among these three structures, the mission was able to handle thousands of patients per year.

After the completion of the main hospital, Mackenzie began to establish out-stations in surrounding areas that brought more patients in contact with the mission, thereby exposing more Chinese to the gospel. The Shantou mission was constructed in such a way that it was built around a "well-equipped center" from which missionaries would "work outwards to surrounding counties," thereby prompting Mackenzie to venture into unfamiliar areas that lacked requisite medical infrastructure.

Mackenzie's work at the Shantou mission was highly Evangelistic; Mackenzie would travel to villages and the individual households within them to establish contact with the locals and preach the virtues of Christianity. Some of these locals would subsequently join Mackenzie in the English Presbyterian Mission, assisting Mackenzie and the other missionaries in spreading the gospel and providing medical care. For those who didn’t join the mission directly, Mackenzie still inspired Chinese Christians who took it upon themselves to build new churches, convert fellow Chinese, and influence missionaries to open new out-stations in underserved areas.

A Mission Printing Press, which was established in 1880, published scriptures and other religious works in Swatow dialect (the local vernacular), which were subsequently printed and distributed. Mackenzie led efforts at the Printing Press to translate the scriptures into the Swatow dialect. Mackenzie worked across several decades, alongside other Reverends such as George Smith and J.C. Gibson, to translate the Epistles of John and Jude from the New Testament. For many years Mackenzie also contributed to the press's monthly publication, titled Church News.