Soleimani was born on 11 March 1957, in the village of Qanat-e Malek, Kerman Province.
In 1975, he began working as a contractor for the Kerman Water Organization.
Soleimani joined the Revolutionary Guard (IRGC) in 1979 following the Iranian Revolution, which saw the Shah fall and Ayatollah Khomeini take power. Reportedly, his training was minimal, but he advanced rapidly. Early in his career as a guardsman, he was stationed in northwestern Iran, and participated in the suppression of a Kurdish separatist uprising in West Azerbaijan Province.
On 22 September 1980, when Saddam Hussein launched an invasion of Iran, setting off the Iran–Iraq War (1980–1988), Soleimani joined the battlefield serving as the leader of a military company, consisting of men from Kerman whom he assembled and trained.
He was seriously injured in Operation Tariq-ol-Qods.
On 17 July 1985, Soleimani opposed the IRGC leadership's plan to deploy forces to two islands in western Arvand Rud, on the Shatt al-Arab River.
After the war, during the 1990s, he was an IRGC commander in Kerman Province.
During the 1999 student revolt in Tehran, Soleimani was one of the IRGC officers who signed a letter to President Mohammad Khatami. The letter stated that if Khatami did not crush the student rebellion, the military would and it might also launch a coup against Khatami.
The exact date of his appointment as commander of the IRGC's Quds Force is not clear, but Ali Alfoneh cites it as between 10 September 1997 and 21 March 1998.
In 1999, Soleimani, along with other senior IRGC commanders, signed a letter to then-President Mohammad Khatami regarding the student protests in July. They wrote "Dear Mr. Khatami, how long do we have to shed tears, sorrow over the events, practice democracy by chaos and insults, and have revolutionary patience at the expense of sabotaging the system? Dear president, if you don't make a revolutionary decision and act according to your Islamic and national missions, tomorrow will be so late and irrecoverable that cannot be even imagined".
Following the September 11 attacks in 2001, senior U.S. State Department official Ryan Crocker flew to Geneva to meet with Iranian diplomats who were under the direction of Soleimani with the purpose of collaborating to destroy the Taliban.
He was considered one of the possible successors to the post of commander of the IRGC when General Yahya Rahim Safavi left this post in 2007.
In 2007, the U.S. included him in a "Designation of Iranian Entities and Individuals for Proliferation Activities and Support for Terrorism", which forbade U.S. citizens from doing business with him.
In March 2007, Soleimani was included on a list of Iranian individuals targeted with sanctions in United Nations Security Council Resolution 1747.
In 2008, he led a group of Iranian investigators looking into the death of Imad Mughniyah.
Soleimani helped arrange a ceasefire between the Iraqi Army and Mahdi Army in March 2008.
In 2009, The Economist stated based on a leaked report that Christopher R. Hill and General Raymond T. Odierno (America's two most senior officials in Baghdad at the time) met with Soleimani in the office of Iraq's president, Jalal Talabani, but withdrew the story after Hill and Odierno denied the occurrence of the meeting.
On 24 January 2011, Soleimani was promoted to Major General by Supreme Leader Ali Khamenei.
On 18 May 2011, he was sanctioned again by the U.S. along with Syrian president Bashar al-Assad and other senior Syrian officials due to his alleged involvement in providing material support to the Syrian government.
On 24 June 2011, the Official Journal of the European Union said the three Iranian Revolutionary Guard members now subject to sanctions had been "providing equipment and support to help the Syrian government suppress protests in Syria".
According to several sources, including Riad Hijab, a former Syrian premier who defected in August 2012, Soleimani was one of the staunchest supporters of the Syrian government of Bashar al-Assad in the Syrian Civil War.
Iranian media reported in 2012 that he might be replaced as the commander of Quds Force in order to allow him to run in the 2013 presidential election.
The retaking of Qusayr in May 2013 from rebel forces and Al-Nusra Front was, according to John Maguire, a former CIA officer in Iraq, "orchestrated" by Soleimani.
In 2014, Soleimani was in the Iraqi city of Amirli, to work with Iraqi forces to push back ISIL militants.
In November 2014, Shi'ite and Kurdish forces under Soleimani's command pushed ISIL out of the Iraqi villages of Jalawla and Saadia in the Diyala Governorate.
In 2015, Soleimani began gathering support from various sources to combat the newly resurgent ISIL and rebel groups which had both successfully taken large swaths of territory from Assad's forces. He was reportedly the main architect of the joint intervention involving Russia as a new partner with Assad and Hezbollah.
In a visit to the Lebanese capital Beirut on 29 January 2015, Soleimani laid wreaths at the graves of the slain Hezbollah members, including Jihad Mughniyah, which strengthened suspicions about a collaboration between Hezbollah and the Quds Force.
In early February 2016, backed by Russian and Syrian air force airstrikes, the 4th Mechanized Division – in close coordination with Hezbollah, the National Defense Forces (NDF), Kata'eb Hezbollah, and Harakat Al-Nujaba – launched an offensive in Aleppo Governorate's northern countryside, which eventually broke the three-year siege of Nubl and Al-Zahraa and cut off the rebels' main supply route from Turkey. According to a senior, non-Syrian security source close to Damascus, Iranian fighters played a crucial role in the conflict. "Qassem Soleimani is there in the same area", he said. In December 2016, new photos emerged of Soleimani at the Citadel of Aleppo, though the exact date of the photos is unknown.
In late March 2017, Soleimani was seen in the northern Hama Governorate countryside in Syria, reportedly aiding Major General Suheil al-Hassan to repel a major rebel offensive.
Trump had expressed a desire to target Soleimani in a 2017 meeting with then National Security Adviser H.R. McMaster. On January 13, 2020, five senior current and former Trump Administration officials told NBC News that Trump had authorized the killing of Soleimani in June 2019 on the condition that he had been involved in the killing of any American, a decision backed by U.S. Secretary of State Mike Pompeo.
In an interview aired in October 2019, he said he was in Lebanon during the 2006 Israel–Hezbollah War to oversee the conflict.
Soleimani was killed on 3 January 2020 around 1:00 a.m. local time (22:00 UTC 2 January), by U.S. drone strike near Baghdad International Airport.
On 4 January, a funeral procession for Soleimani was held in Baghdad with thousands of mourners in attendance, waving Iraqi and militia flags and chanting "death to America, death to Israel". The procession started at the Al-Kadhimiya Mosque in Baghdad. Iraq's prime minister, Adil Abdul-Mahdi, and leaders of Iran-backed militias attended the funeral procession. Soleimani's remains were taken to the holy Shia cities of Karbala and Najaf.
On 6 January, the body of Soleimani and other casualties arrived at the Iranian capital Tehran. Huge crowds, reportedly hundreds of thousands or millions, packed the streets. Supreme Leader Ali Khamenei, who had a close relationship with Soleimani, led the traditional Islamic prayer for the dead, weeping at one point in front of the flag-draped coffins.
On 7 January 2020, a stampede took place at the burial procession for Soleimani in Kerman attended by hundreds of thousands of mourners, killing 56 and injuring 212 more.
On 8 January 2020, the Iranian military responded to Soleimani's death by launching ballistic missiles at two U.S. bases in Iraq, resulting in no reported casualties.
On 13 January 2020, Syrian Minister of Defense, Ali Abdullah Ayyoub, presented the medal of "The Champion of the Syrian Arab Republic", which President Bashar Al-Assad granted posthumously to Qassem Soleimani, to his Iranian counterpart, Amir Hatami.