Jakob Smits was born in Rotterdam on 9 July 1855. His father, Frans Smits, owned a large decoration business there. Jakob was the eldest of six children. His childhood and teenage years are poorly documented. He was already creative at a young age. At only 15 years of age he painted Moeder bij de wieg. Jakob studied at the academy, but everyone expected him to follow in his fathers footsteps as a decorator. Jakob, however, was always in doubt about being a decorator or choosing the real art. He initially entered the family business, but he soon realised that this was not what he really wanted in life. At the age of 18, he left for Brussels where he studied at the academy and stayed for three years until illness forced him to return to Rotterdam. After a while he returned to work as a decorator, but it remained difficult for Smits to settle in this job. In 1879 he got engaged to Anna Doetje Kramer. Despite this commitment, Smits moved to Munich, Vienna and finally Rome.
In 1882, he married Anna Doetje Kramer. From this marriage two daughters were born, Theodora and Annie. The couple settled in Amsterdam, where Smits carried out his first decoration projects, including some projects for the art museum, Boijmans, in Rotterdam. He also taught at the Haarlem school of applied art. As before, the decoration work soon started to annoy him and he grew more and more tempted to entirely pursue art. In the winter of 1885–1886 the tension mounted and Smits left his family, eventually moving to Brussels.
The Campine landscapes fascinated him in such a way that in 1888 he settled permanently in the hamlet Achterbos in Mol. There, he moved into a small farmhouse, which he would later buy for 2,000 francs (around €50). He gradually expanded this into the Malvinahof. That same year, he married Malvina Dedeyn, daughter of a lawyer from Brussels, who later disinherited her for the marriage. Despite the poverty, these were perhaps the happiest years of Smits life: he worked tirelessly and continuously on the creation of what he would later call my simple work, symbolic, poetic and real. In 1897 he received a gold medal for his large watercolours on a background of gold leaf at exhibitions in Munich and Dresden. He also painted many portraits, especially of Malvina and their children Boby, Marguerite and Kobe. In 1899, however, destiny struck: within the space of a few days, he lost both his little daughter Alice and his wife.
Two years after the death of Malvina, he married the much younger Josine Van Cauteren. In the same year, 1901, the now 46-year-old artist held his first individual exhibition in Antwerp. Artists, art connoisseurs and critics were full of praise, but Smits did not sell anything. The exhibited masterpiece De vader van de veroordeelde would be purchased later that year by the museum of Brussels. Smits finances had improved by then, but the responsibilities for his family continued to give him a hard time: in 1903 he took in both his parents, who were ruined by theft. From then on, he had to support nine family members.
In 1907, at the request of the Mol Town Council, Jakob Smits organised an international exhibition of artists who painted landscapes of Mol and its surroundings. No fewer than 68 painters participated. Among them were Germans, Dutchmen, Englishmen and Americans. The term Molse School was born. In 1910 Smits published an album with 25 etchings, dedicated to Queen Elisabeth. In 1912, the young Dirk Baksteen became his apprentice and assistant.
At the beginning of the First World War, Smits laid down brush and chalk and became chairman of the Committee for the Assistance and Food Supply of the canton Mol. After the war, he returned to work full of enthusiasm, and he astonished the art world with paintings which showed a completely new vision and style. From 1923 onwards, his state of health steadily deteriorated. Smits suffered from cancer of the jawbone, which caused him severe pain. Being a fighter, he did not want to admit defeat and he continued to paint. On 15 February 1928, he died of a heart attack. He is buried in the cemetery of Achterbos in Mol. A bronze Moeder en Kind, a sculpture by George Minne, adorns his grave. His wife Josine outlived him by 28 years. After her death, the Malvinahof was sold.