Justus Hiddes Halbertsma (West Frisian: Joast Hiddes Halbertsma [joǝst ˈhɪdəs ˈhɔlbǝtsma]; Dutch: Joost Hiddes Halbertsma [joːst ˈɦɪdəs ˈɦɑlbǝrtsmaː]; 23 October 1789 – 27 February 1869) was a Frisian writer, poet, minister, lexicographer and linguist. Today, he is primarily known for the poetry and short story collection De Lapekoer fan Gabe Skroar, which he wrote with his brother Eeltsje, publishing the first edition in 1822. Afterwards, this work was continually expanded, and also came to include contributions by a third brother, Tsjalling, until all the Halbertsma Brothers' prose and poetry was posthumously collected in 1871 to become the famous work Rimen en Teltsjes. Although the literary value of this collection was later disputed by some critics, it is undeniable that Rimen en Teltsjes played a role of crucial importance in the development of a new literary tradition after Western Frisian had been used almost exclusively as a spoken language for three centuries.

Justus Hiddes Halbertsma was born on 23 October 1789 in the village of Grou, in the central part of the Dutch province of Friesland, in the house of his parents on Kowemerk ("Cow Market") street. He was the eldest son of the baker and small-time merchant Hidde Joasts Halbertsma (1756–1809) and his wife Ruerdtsje (or Riurtk) Tsjallings Binnerts (1767–1809). He had three younger brothers: Tsjalling (1792–1852), Binnert (1795–1847), and Eeltsje (1797–1858). Two children who were born later died in early childhood, the little boy in 1803, and the little girl in 1805. The four brothers were very close, possibly as a consequence of the fact that both their parents died at a relatively young age in 1809, when Justus was just twenty years of age and the others were even younger. Justus, Tsjalling and Eeltsje, who, as authors, became known as the Brothers Halbertsma later in life, were much like their father, while Binnert more resembled their mother.

Ruerdtsje Binnerts was a scion of a prominent family in Grou. Her people were Mennonites, and although her husband had been raised a Calvinist, he converted after marrying her. From Justus' letters Ruerdtsje emerges as a smart businesswoman, a loving mother, and a deeply religious person. About Hidde Halbertsma, the father, much less is known. It is thought that he might have been a mariner before his marriage. He is described as a gentle soul, who was, however, apt to take offence, and could be quite sharp-tongued in such cases. In 1784, he published a long Dutch-language poem under the title Schrikkelijke IJsgang en Overstroominge in Gelderland ("Terrible Ice-drift and Flooding in Gelderland"). From this intriguing work it is clear that his sons' literary talents were a family trait.

In 1858, Justus Halbertsma explained the difference between his parents' families when he wrote: "One cannot deny the Halbertsmas a greater skillfulness, speed of thought, a greater adroitness, quickness, and talent than the family of Ruerdtsje Tsjallings; but wat help was that to them against the poverty which overcame most of them, while Ruerdtsje Tsjallings' family for the most part maintain prosperity to this day as part of the dignified middle class?" Against the superior power of those who calmly and calculatedly grew rich, he wrote somewhere else, the Halbertsmas could only "avenge themselves through satire."

Halbertsma's mother Ruerdtsje was the main force behind the thorough education her sons received. Justus she sent to the French school in the provincial capital of Leeuwarden for a year, and after that, she enrolled him in the Latin school in Leeuwarden from 1801 to 1806. At the advice of his mother and the Mennonite minister Jan Brouwer, from Leeuwarden, Justus Halbertsma chose a clerical career, for which he studied theology at the Mennonite Seminary in Amsterdam from 1807 to 1813. In that period he also immersed himself in the study of the North Germanic languages. In 1814, Halbertsma became minister in Bolsward, where he remained until 1821. Afterwards, he served the Mennonite congregation in the city of Deventer, in the province of Overijssel, from 1822 to his retirement in 1856.

Halbertsma married Johanna Iskjen Hoekema (1794–1847), a Mennonite minister's daughter from Workum, who came from a well-to-do middle-class family, on 10 May 1816. Through his wife Halbertsma attained possession of the farmstead Westerein, near Workum, where he and his family often spent a couple of weeks in summer. Apart from those holidays, he lived out his entire life in Deventer. Halbertsma and his wife had five sons from a good marriage, which was however not without its share of problems. Of these sons Petrus, Hidde, and Tsjalling studied linguistics or medicine, while Watse en Binnert became mariners. As a father, Halbertsma experienced a large amount of grief, as his son Petrus died in 1851 in a psychiatric hospital, while Binnert died in 1861, and Hidde took his own life in 1865.

Halbertsma had been greatly influenced in his student years by his acquaintance with the well-to-do and influential Amsterdam merchant Jeronimo de Vries, who championed a national art, inspired by the Dutch Golden Age. These ideas flew in the face of more modern notions advocated by writers such as Hiëronymus van Alphen and Johannes Klinker. For Halbertsma, who was first and foremost a Frisian, and only secondly a Dutchman, this meant an orientation towards national Frisian ideals, from which emanated two goals he set himself in life. Firstly, he wanted to preserve the Western Frisian language by using it for writing again after it had been used almost exclusively as a spoken language for three centuries. From that it followed that he had to get the Frisians to read in their own language (otherwise, writing it would not be of much use), and that he should record the Frisian vocabulary in a dictionary, which would be the first dictionary ever of the Frisian language. And secondly, Halbertsma wanted to put renowned Frisian people from the past in the spotlight, to serve as an example for his contemporaries.

To attain his first goal, Halbertsma had to use his writings to penetrate the daily life of the Frisian people. This he achieved by authoring folk literature with his brother Eeltsje. The state and social status of the Western Frisian language at that time becomes clear if one observes the fact that Halbertsma and his brothers, though they laboured tirelessly for the use of Frisian as a written language for poetry and prose, lapsed into Dutch for their correspondence with each other, and apparently did not feel that was in any way strange. As Halbertsma remained the editor of Eeltsje's work for his entire life, their poetry and short fiction were strongly connected and published together from the very beginning. For that reason the linguist Foeke Buitenrust Hettema would describe Halbertsma later as the 'literary agent' of his brothers Eeltsje and Tsjalling. In 1822, their early works were collected under the title De Lapekoer fan Gabe Skroar ("Gabe Tailor's Rag Basket"; original, archaic spelling: De Lape Koer fen Gabe Skroor), a booklet consisting of 36 pages, and including six poems and one short story. This publication was attributed to the fictional 'Gabe Skroar', a lame farmer's son who became a tailor and a writer, but died young. This character was in all probability a creation of Eeltsje's. Hiding behind such a fictional author was fairly normal at that time.