Nationalist Salafies

• Islamic Army in Iraq (Al-Jaish Al-Islami fil-Iraq)
• Sufi Naqshbandi Iraqis (Naqshabandiya Army)
• Iraqi Islamic Resistance Front (JAAMI Iraqi nationalists)
• Jaish al-Mujahideen
• Mujahideen Battalions of the Salafi Group of Iraq
• Islamic Salafist Boy Scout Battalions (Kataab Ashbal Al Islam Al Salafi)
• Mohammad's Army (aka Jeish Muhammad)
  A guerrilla group opposed to the coalition forces, composed primarily of Sunnis believed to have Baathist ties.

Pan-Arab Nationalists

• Nasserites

Jihadist Salafies

• Islamic State of Iraq (till Nov '06, Mujahideen Shura Council)
  Umbrella organization and de facto state
  • Al Qaeda in Iraq
  • Jeish al-Fatiheen (Conquering Army)
  • Jund al-Sahaba (Soldiers of the Sahaba)
  • Katbiyan Ansar Al-Tawhid wal Sunnah (Brigades of Monotheism and Religious Conservatism)
  • Jeish al-Taiifa al-Mansoura (Army of the Victorious Sect)
  • Monotheism Supporters Brigades
  • Saray al-Jihad Group
  • al-Ghuraba Brigades
  • al-Ahwal Brigades
• Jama'at al-Tawhid wal-Jihad
  A now-defunct militant organization led by al-Zarqawi preceding AQI.
• Jamaat Ansar al-Sunna (formerly Jaish Ansar al-Sunna)
  
• Ansar al-Islam
• Black Banner Organization (ar-Rayat as-Sawda)
• Asaeb Ahl el-Iraq (Factions of the People of Iraq)
• Wakefulness and Holy War
  
• Abu Theeb's group
• Jaish Abi Baker's group

Baathists

• Fedayeen Saddam ("Saddam's Men of Sacrifice")
  A paramilitary organization loyal to the former Baathist regime of Saddam Hussein.
• The Return (al-Awda)
  composed of former Ba'ath Party officials, intelligence agents, former members of the Republican Guard, the Special Republican Guard and Fedayeen Saddam militia.
• General Command of the Armed Forces, Resistance and Liberation in Iraq
• Iraqi Popular Army
• New Return
• Patriotic Front
• Political Media Organ of the Ba‘ath Party (Jihaz al-Iilam al-Siasi lil hizb al-Baath)
• Popular Resistance for the Liberation of Iraq
• Al-Abud Network

• Iraqi Army
  The Iraqi Army is a component of the Iraqi Security Forces tasked with assuming responsibility for all Iraqi land-based military operations following the 2003 Invasion of Iraq.
• Iraqi Air Force
• Iraqi Police
  The Iraqi Police are the organic civil police force of the Republic of Iraq. There are three main branches.
  • Iraqi Police Service (IPS): Responsible for the day to day patrolling of cities around most crimes.
  • National Police (NP): Paramilitary force for counterinsurgency, public disorder and counter terrorist tasks.
  • Supporting Forces: Remaining police organizations, primarily the Department of Border Enforcement (DBE).
• Facilities Protection Service
  A paramilitary force responsible for protecting government buildings and facilities.

Shia militia

• Mahdi Army (Jaish-i-Mahdi)(جيش المهدي)
  The Mahdi Army is a militia force created by the Iraqi Shia cleric Muqtada al-Sadr in June of 2003.
• Abu Deraa's Mahdi Army faction
  In the fall of 2006, Abu Deraa and his supporters formed their own militia.
• Badr Organization (originally Badr Brigade/Bader Corps) (منظمة بدر)
  The armed wing of the Supreme Council for the Islamic Revolution in Iraq (SCIRI).
• Soldiers of Heaven
  an armed Iraqi Shi'a sect.
• Asaeb Ahl Al-Haq
  
• Special Groups (Iraq) Iranian-backed militants

Kurdish militias

• Peshmerga
  - term used by Kurds to refer to armed Kurdish fighters.
• Kurdistan Workers Party or PKK. A militant separatist organization whose goal is the creation of a Kurdish state. Currently taking refuge in Iraqi Kurdistan.
• Party for a Free Life in Kurdistan or PJAK. A militant separatist organization whose goal is overthrowing the Islamic government of Iran. Currently taking refuge in Iraqi Kurdistan.

Sunni militias

• Awakening groups
• 1920 Revolution Brigades
• Jaish al-Rashideen
• Islamic Front for the Iraqi Resistance (al-Jabha al-Islamiya lil-Moqawama al-Iraqiya - JAMI)
• Hamas of Iraq