Stanisław Sosabowski was born on 8 May 1892 in Stanisławowo into the family of Władysław and Franciszka née Grabarska. Following his father's death (in 1904), he provided paid tutoring to other students because his family was in a difficult financial situation. In 1905, he became involved in the independence movement, first as part of the Association of the Polish Youth "Zet", then in the Organisation of Independent Youth Zarzewie. He also became a member of the Polish Military Association, where he was actively involved under the pseudonym "Stanisław Węglarz".

After passing his matura examination with honours in 1910, he continued his education with a one-year course at the Higher School of Commerce in Kraków. Upon his return to Stanisławowo, he took command of the 24th Rifle Squadron with the rank of cadet. In 1913, Sosabowski did his basic military service in the Austro-Hungarian army, and on 1 February 1914 he was named inspecting officer of Regional Headquarters No. 1 of the Polish Rifle Squads in Lviv.

In the first days of August 1914, Sosabowski came to Stanisławowo to join the 58th Galician Infantry Regiment. As a private, he fought in Galicia, Slovakia, in the Battle of Gorlice in May 1915. In June 1915, he was badly wounded in a skirmish against Russians near Brest-on-the-Bug. After many months of recovery, he was assigned to the Censorship Office in Zolochiv, and was then sent to the command of the 2nd Army in Lviv, where he served until 6 March 1917. At the beginning of 1918, in Lublin, he began cooperation with the commander of the Polish Military Organisation for areas occupied by Austria-Hungary, Lt. Col. Stanisław Burhardt-Bukacki.

In November 1918, Stanisław Sosabowski became an officer in the reborn Polish Army. He was named captain and took up the position of Head of the Economic Department of the Liquidation Committee in Lublin. In 1919, was seconded as a representative of the Ministry of Military Affairs to the General Liquidation Office. Due to an injured leg, he was unable to fight against the Bolsheviks, and served in Branch IV of the staff of the Ministry of Military Affairs. In November 1920, he was promoted to major.

From 1922 to 1923, he was a student at the War College. In 1927, he was named lieutenant colonel and assigned to the frontline. As battalion commander in the 75th Infantry Regiment, he was garrison commander in Rybnik. A year later, he became deputy commander of the 3rd Podhale Rifle Regiment. From 1929 to 1937, he was involved with the War College, first as a lecturer and then as head of the Department of Operational Staff Service for first-year students. In 1937, he took command of the 9th Legions Infantry Regiment, and in 1939 - 21st Infantry Regiment (Children of Warsaw) He was also promoted to colonel.

In September 1939, the 21st Infantry Regiment under Sosabowski's command, which was part of the 8th Infantry Division, fought near Przasnysz. After retreating to Warsaw, he fought with his regiment in various places, including the Grochów District. For his exemplary conduct during the Polish campaign and for his personal acts of bravery, he was awarded the Silver Cross of the War Order of Virtuti Militari, 5th class, in London on 22 October 1947.

Once Warsaw surrendered, Sosabowski was captured by the Germans, but he managed to escape after three days. He made contact with emerging resistance structures of the Polish Victory Service. There, he organised and was in charge of the Łódź District of the Polish Victory Service. In November 1939, through the territories occupied by the Soviet Union and then Hungary, he managed to reach France, where he helped build Polish army structures in exile. He became deputy commander of the 4th Infantry Division which, after the French defeat, had to evacuate to Britain.

He was given command of the 4th Cadre Rifle Brigade, which, from January 1941 onwards, was to act as a preparation and training centre for candidates to parachute into Poland. By Gen. Sikorski's decision, the brigade was given a new name of the 1st Parachute Brigade on 23 September 1941, a unit reporting directly to the Commander-in-Chief. Stanisław Sosabowski became brigade commander and on 15 June 1944, he became brigadier general.

The 1st Parachute Brigade, commanded by General Sosabowski, participated in Operation Market Garden - the largest airborne military operation of the Second World War. In September 1944, the soldiers landed near Arnhem in the Netherlands. Fighting against Germans, the brigade suffered considerable losses while defending itself against German soldiers advancing on Allied positions. Gen. Sosabowski was baselessly blamed for the failure of Operation Market Garden by the British. On 27 December 1944, he was stripped of his command of the Parachute Brigade.

Gen. Sosabowski became the Inspector of Staging and Guarding Units. After demobilisation of 1948, he decided to stay in the UK, where he worked as a manual labourer. He died in Hillingdon on 25 September 1967. Two years later, his ashes were brought to Poland and buried in the Powązki Military Cemetery in Warsaw. In 2018, he was awarded the Order of the White Eagle by the President of Poland, Andrzej Duda.