Brigadier General Nimcaan Yusuf Osman (Somali: Nimcaan Yuusuf Cismaan, Arabic: نعمان يوسف عثمان) nicknamed Gahnug (Somali: Gaaxnuug) is a Somaliland military officer serving as the Chief of the General Staff of the Somaliland Armed Forces since January 23, 2025.

Appointed by president Abdirahman Mohamed Abdullahi (Irro), he is the youngest officer to hold this position in Somaliland's history.

Prior to his appointment as Chief of Staff, he commanded the Gamadiid Special Forces and the Presidential Guard Unit during the tenure of former president Ahmed Mohamed Mohamoud (Siilaanyo).

[5][3] The decision was framed as part of a broader initiative to inject "contemporary military wisdom" into Somaliland's defense strategy.

[3] Under Osman’s leadership, the Somaliland Armed Forces announced significant reforms, including a 50% annual salary hike for military personnel, effective 2025, as part of a pledged 250% increase over Irro’s term, implementation of the IRIS Biometric Registration System to eliminate payroll fraud and "ghost personnel", as well as plans to upgrade equipment and training programs.