In the spritual tradition of Islam, a Wali (lit. protector or guardian), or Waliullah/WaliAllah is a friend of God.

Usually these people are members of Sufi (mystic) communities who are considered to have a special relationship with Allah. Some of them are believed to have directly conversed with God.

A wali is usually considered a "saint" by their community after death, and a shrine may grow around the person's tomb.

Famous Walis include Ali, son-in-law of Muhammed; Fatima, daughter of the prophet; and Rabia al-Adawiya, a (female) Sufi poet of Iraq who was born a slave.

The title of wali is sometimes applied to non-Muslims, such as Khalil Gibran, the poet of Lebanon, who was a Maronite Catholic. All prophets, by definition, are also walis.