Born in Cairo in 1934, Osman was a law student at Cairo University before becoming a journalist. He moved to London in 1964. He became interested in possible links between the Bible and recent archaeological discoveries in Egypt, looking for possible reasons for the historical tension between Egypt and Israel. His first theory was that Joseph was the father-in-law of Amenhotep III, Yuya. In 1987 this claim provided the basis for his first book, Stranger in the Valley of the Kings.

Osman identified the Semitic-born Egyptian official Joseph with the Egyptian official Yuya, and asserted the identification of Hebrew liberator Moses with the Egyptian pharaoh Akhenaten. Ahmed Osman has even claimed that Moses and Akhenaten were the same person, supporting his belief by interpreting aspects of biblical and Egyptian history. He alleges that Atenism can be considered monotheistic and related to Judaism, and includes other similarities, including a ban on idol worship and the similarity of the name Aten to the Hebrew Adon, or "Lord". This would mesh with Osman's other claim that Akhenaten's maternal grandfather Yuya was the same person as the Biblical Joseph.

Osman's positions are in conflict with of Egyptology mainstream beliefs and parts of the conventional Egyptian chronology. Some Egyptologists have gone as far as rejecting them as unacademic conjecture while others do not consider them worth refuting. Al-Ahram Weekly | Profile | Ahmed Osman: Beyond beliefDonald Redford wrote a scathing review of Stranger in the Valley of the Kings for BAR. Osman states that the reason mainstream Egyptologists do not accept his theories and the theories of others is because, "Egyptologists have established their careers on their interpretations", and that to accept other theories could give them less authority.

Osman has a Master's Degree in Egyptology.

• Stranger in the Valley of the Kings: Solving the Mystery of an Ancient Egyptian Mummy (1987)

alternate edition: Stranger in the Valley of the Kings: The Identification of Yuya as the Patriarch Joseph (1988)

alternate edition: Hebrew Pharaohs of Egypt: The Secret Lineage of the Patriarch Joseph (2003)

• Moses: Pharaoh of Egypt: The Mystery of Akhenaten Resolved (1990)

alternate edition: Moses and Akhenaten: The Secret History of Egypt at the Time of the Exodus (2002)

• The House of the Messiah: Controversial Revelations on the Historical Jesus (1992)

alternate edition: The House of the Messiah: A Brilliant New Solution to the Enduring Mystery of the Historical Jesus (1994)

alternate edition: Jesus in the House of the Pharaohs: The Essene Revelations on the Historical Jesus (2004)

• Out of Egypt: The Roots of Christianity Revealed (1999)
• Out of Egypt: Embracing the Roots of Western Theology (2001-2)
• Christianity: An Ancient Egyptian Religion (2005)