Al-Shabaab (Harakat al-Shabaab al-Mujahideen) is a jihadi insurgent group in Somalia. It draws from a Salafi-Wahhabi strand of Sunni Islam and is affiliated with al-Qaeda.

The group developed in the early 2000s and at one point controlled much of Somalia, including the capital Mogadishu and major port cities. They now control only pockets of territory however. Ahmad Omar is the current leader of the group, having taken over from Ahmad Abdi Godane who was killed on 1 September 2014 by a US airstrike. Estimates of the group's size range from 7,000-9,000.

Many members of the group embrace the idea of a Greater Somalia; others follow a more international expansionist jihadi philosophy as espoused by al-Qaeda. Since December 2012, al-Shabaab has been a recognised affiliate of the al-Qaeda franchise.

Al-Shabaab calls for stringent application of sharia, which is seen as a mark of piety. The group has presented itself as the only legitimate representative of the Somali people and the vehicle through which Somali honour can be restored and imperial ambitions of neighbours and foreign powers further afield can be fended off. Many analysts believe the group enjoys considerable local grassroots sympathy and support. However, many accuse them of using the rhetoric of the Quran and sharia to impose their authority on communities and followers but then exploit that for the benefit of the group above the community, and al-Shabaab leaders above all.

While al-Shabaab's primary focus remains largely in Somalia, it has attracted a sizable number of foreign fighters. The group's internationalist ideology has led it to carry out attacks abroad, many of these have targeted Kenya, though Ethiopia and Uganda have also been attacked.