West Irian Jaya (Indonesian: Irian Jaya Barat) is a province of Indonesia on the western end of the island of New Guinea. It covers the Bird's Head Pensinsula (Indonesian: Kepala Burung) and surrounding islands.

West Irian Jaya was created from the western portion of Papua province in February 2003. The split remains controversial. Supporters, including those in the central government in Jakarta and immigrants to Papua from elsewhere in Indonesia, argue that the creation of the new province will help ensure the efficient management of resources and fair distribution of services. The split is widely opposed in Papua itself, where it is viewed as a violation of special autonomy laws governing Papua, and as an effort to quell the Papuan separatist movement (see Papua history).

In November 2004, an Indonesian court agreed that the split violated Papua's autonomy laws. However, the court ruled that because the new province had already been created, it should remain separate from Papua. The ruling also prohibited the creation of another proposed province, Central Irian Jaya, because the split was not yet completed.

The capital of Irian Jaya Barat is in Manokwari . The province contains one other city, Sorong , and seven regencies (districts):

• Manokwari
• Fak-Fak
• Sorong Selatan (capital Teminabuan )
• Raja Ampat (capital Waisai )
• Kaimana
• Teluk Bintuni (capital Bintuni )
• Teluk Wondama (capital Rasiei )