Dera Allah Yar (Urdu: ڈیرہ اللہ یار) is a city and the headquarters of the Jaffarabad District located in Pakistan's Balochistan province.

Dera Allahyar became part of newly created Kalat District in 1954.

Dera Allahyar merged into newly created Nasirabad District in 1984.

The city was renamed after the assassination of Mir Allahyar Khan Khosa, a political leader from the area.

According to 2023 Pakistani census Population of Dera Allahyar Subdivision is 302,498 of which 188,011 spoke Balochi, 44,211 Sindhi, 34,493 Saraiki, 31,374 Brahui, 1,273 Pashto, 612 Urdu, 609 Hindko 390 Punjabi & 1,515 others.