Dejazmach Balcha Safo (Amharic: ባልቻ ሳፎ; 1863 – 6 November 1936), popularly referred to by his horse-name Abba Nefso, was an Ethiopian military commander and lord protector of the crown, who served in both the First and Second Italo-Ethiopian Wars.

He was later a key member of the conservative provincial elite who, in the 1920s, were often at odds with the modernising reforms and rising power of the Regent, Ras Tafari Makonnen.

Tafari Makonnen would later force Dejazmach Balcha into retirement, albeit an honourable one, in 1928, from which he would emerge in 1935 to fight against the Fascist invasion, resulting in his death in 1936.

Originally of humble birth, Balcha Safo, along with Habte Giyorgis Dinagde, was one of many castrated prisoners of war taken during Menelik II's expansions into the Hadiya state under Hassan Enjamo between 1875 and 1889.

A blunt old warrior, he did not trust the young regent, unlike most other warlords who by this time had all submitted themselves to Tafari in his ambition to consolidate power.

Balcha arrived 11 February with several thousand men, most of whom he left camped right outside of Addis Ababa at an area called Nifas Silk.

[3] Major Mesfin Sileshi, an agent of the imperial government in exile who was coordinating resistance in occupied Ethiopia, writes of his fate in a letter to Haile Selassie I thus: The enemy went to where his Excellency Dejazmatch Balcha lived, and campaigned against him.