Kyai Haji Ahmad Dahlan (born in Yogyakarta, August 1, 1868 – died in Yogyakarta, February 23, 1923 at age 54 years) is a National Hero of Indonesia. He waswas the fourth son of seven children of a family of KH Abu Bakr. KH Abu Bakr was a scholar and a leading preacher in the Great Mosque of Yogyakarta Sultanate at that time, and the mother of KH Ahmad Dahlan was the daughter of H. Ibrahim, who also serves Ngayogyakarta Sultanate rulers at that time.
Forename KH. Ahmad Muhammad Dahlan is Dervish. He is the fourth child of seven brothers who all female relatives, except her youngest sister. He included the twelfth descendant of Maulana Malik Ibrahim, one of the foremost among Walisongo, the pioneer of the spread of Islam in Java.  The genealogy is Maulana Malik Ibrahim, Maulana Ishaq, Maulana ‘Ainul Yaqin, Maulana Muhammad Fadlullah (Sunan Prapen), Maulana Sulaiman Ki Ageng Gribig (Djatinom), Demat Djurung Sapisan omen readers, Demat Djurung Kapindo omen readers, Kyai Ilyas, Kyai Murtadla, KH. Mohammad Sulaiman, KH. Abu Bakr, and Muhammad Darwisy (Ahmad Dahlan). 
At the age of 15, he went to Hajj and stayed in Mecca for five years. In this period, Ahmad Dahlan began to interact with the ideas in the Islamic reformers such as Muhammad Abduh, Al-Afghani, Rashid Rida and Ibn Taymiyyah. When returned to his village in 1888, he changed the name to Ahmad Dahlan.
In 1903, he departed back to Mecca and settled for two years. At this time, he had studied to Sheikh Ahmad Khatib who is also the teacher of the founder of NU, KH. Hasyim Asyari. In 1912, he founded the village Kauman Muhammadiyah, Yogyakarta.
On his return from Mecca, he married Siti Walidah, his own cousin, the son of Kyai Haji Fadhil prince, later known as Nyai Ahmad Dahlan, a National Pahlawanan and founder Aisyiyah. From his marriage to Siti Walidah, KH. Ahmad Dahlan have six children namely Djohanah, Siradj Dahlan, Siti Busyro, Irfan Dahlan, Siti Aisyah, Siti Zaharah.  In addition, KH. Ahmad Dahlan had also married Nyai Abdullah, widow of H. Abdullah. He also never married Nyai Rum, brother of Kyai Munawwir Krapyak. KH. Ahmad Dahlan also has a son from his marriage with Ayesha Nyai (brother Adjengan prince) named Dandanah Cianjur. He had also married to Yasin Pakualaman Nyai Yogyakarta. 
KH. Ahmad Dahlan was buried in KarangKajen, Yogyakarta.