Achefer (Amharic: አቸፈር) was a woreda in Amhara Region, Ethiopia.
[1] Part of the Mirab Gojjam Zone, Achefer was bordered on the south by the Agew Awi Zone, on the west by the Semien Gondar Zone, on the north by Lake Tana, on the northeast by Bahir Dar Zuria, and on the southeast by Merawi; the Lesser Abay River defined the woreda's eastern boundary.
The administrative center was Yesmala; other towns in Achefer included Durbete, Liben, Kunzela, Chiba and Wandege.
Based on figures published by the Central Statistical Agency in 2005, this woreda has an estimated total population of 326,195, of whom 160,763 are men and 165,432 are women; 24,565 or 7.53% of its population are urban dwellers, which is about the same as the Zone average of 7.6%.
The majority of the inhabitants practiced Ethiopian Orthodox Christianity, with 98.77% reporting that as their religion, while 1.18% were Muslim.