Khawaja Reazuddin Atash [ خواجہ ریاض الدین عطش ] was a noted Urdu poet and writer from Pakistan. He wrote ghazals, nazms and hamd-o-na`at and authored books on the Urdu language and biography of Dr. Mubarak Azimabadi. He published his poems in three volumes: Saughat-e-Junoon, a collection of ghazals; Jashn-e-Junoon, a collection of nazms; and Vird-e-Nafas, a collection of Hamd-o-Naat. He also published Daagh ka Akhri Charagh, a biography of the famous Urdu poet Dr. Mubarak Azimabadi, a disciple of Daagh Dehlavi, Urdu ka Shajra-e-Nasab, a linguistic research and reference work on the Urdu language, and Urdu Dushman Tehreek ke Sau Saal, a collection of investigative papers and articles about anti-Urdu movements.

Atash was born on 4 March 1925, (8th Sha'ban, 1342 H) in the historic city of Azimabad (Patna) Bihar, India. He spent his early life in pre-partitioned India and migrated to Dhaka, East Pakistan (Bangladesh) in 1947, where he lived until 1971.

Atash joined the Royal Air Force and served on warfronts in Burma, Thailand and Singapore during World War II. In Dhaka, he worked hard to support a large joint family. Later, he started his own business of commercial art and advertising, and before leaving Dhaka for Karachi, he was a senior officer of Associated Consulting Engineers, a US engineering consultancy firm, which provided technical services to Pakistan's Water & Power Development Authority.

Following political and civil unrest in the then East Pakistan, leading to the creation of Bangladesh, Atash migrated to Karachi, (West) Pakistan.

Atash belonged to a literary family hailing from Delhi and Azimabad, Bihar. He started writing poetry from an early age. He participated actively in 'mushairas' and literary sittings. His popularity rose in the literary circles of Pakistan, India and USA. He also wrote lyrics for film songs and commercial jingles. He founded Bazm-e Sukhan in Dhaka, Karachi and Chicago.

His grandfather, Syed Khawaja Fakhruddin Sukhan Dehlavi was a renowned poet and writer of the late 19th century. Sukhan, a disciple of Mirza Ghalib, published many books including Divan-e-Sukhan, a collection of poems, and Sarosh e Sukhan, a fiction novel (داستان), which are considered early Urdu classics.

Atash spent the last ten years of his life in the suburbs of Chicago, Illinois, USA, where he became a popular literary personality. He actively participated in literary symposiums and mushairas and wrote regularly for Urdu newspapers and periodicals of North America, Pakistan and India.

He was accorded several literary awards, including the AMUAAGC Ghalib Award for his lifelong literary services.

Atash died in January 2001. He is buried at Chicago's Rosehill Cemetery