Joseph Montwill graduated from the Vilnius Gymnasium in 1866 and the Faculty of Law of St Petersburg University in 1872.
Later he studied sociology and economics in Berlin, Vienna, and Kraków.
After graduating, he returned to Lithuania. He lived and farmed in Šėta (Kėdainiai district) for some time.
In 1885, he became a director of the Vilnius Land Bank, was elected a member of the Vilnius City Duma, and from 1897 he was elected the Vilnius burgomaster.
In 1907 he was elected a representative of the State Duma.
As the head of the Vilnius Land Bank, Montvila took advantage of opportunities to develop socially beneficial activities and took an active part in the public life of Vilnius.
J. Montwill died in Vilnius in 1911 and was buried in Rossy Cemetery in Vilnius. In 1911, a marble memorial plaque with an inscription dedicated to him was unveiled in the Church of the Assumption of the Virgin Mary or Franciscans (Trakų Street).
In 1914, a tombstone was erected in the Rossy cemetery - a sculpture of an angel (sculpted by Z. J. Otto), cast in the workshop of L. Kranz in Warsaw.
Montwill was best known as a supporter of construction, scientific and artistic institutions and societies.
- In 1895, following the European example, he started the construction of cooperative house complexes in Vilnius, then called colonies. Such colonies were built in Nowe Miasto (Naujamiestis), Sznipiszki (Šnipiškės), Rossy (Rasų) Street, and near Lukiszki (Lukiškės) Square - they can be called new parts of the urban model of the city. The colony near Lukiškių Square still stands today and is one of the most beautiful buildings in Vilnius.
- Montvila was involved in charitable activities, founding and supporting more than 20 public organisations, including
- The Children's Welfare Society
- The Vilnius City Poor People's Charity Institution
- The Orphanage of St. Vincent and St. Paul
- The St. Zita's Maids' Society
- The "Pieno lašas ( Drop of milk)" and "Pietūs veltui ( Lunch for free)" campaigns, and others.
- Thanks to his efforts, children's summer recreation camps, a children's foster care society, music and art schools, an orphanage, a hostel, a dispensary for the poor, and free technical drawing and drafting classes at the Vilnius School of Drawing were established.
- Together with his brother Stanislaw, J. Montwill founded the Joseph and Stanislaw Montwill Brothers Foundation, which financially supported the Vilnius Society of Friends of Science, the Polish Art Lovers' Society "Liutnia" and other similar organizations. The Foundation's funds were used to renovate the premises of the Franciscan monastery and to house several charitable organizations.
- Together with Brother Stanislovas Montvila, he also built theatres in Vilnius and Panevėžys.
In commemoration of the 20th anniversary of the death of J. Montwill, in 1932 in the square between Trakų and Pranciškonų streets in Vilnius a monument was built (sculptor Boleslovas Balzukevičius, architect Jonas Brovskis). A 1.7 m high bronze figure of J. Montvila sitting in a chair is placed on a 2.2 m high hewn granite pedestal. In interwar Vilnius, this Franciscan monastery square monument was the first full-figured monument
After J. Montvila's death, a street is dedicated to him.