Within carbon suboxide C2O devised from ab initio in ground state two-dimensional structure, finite spin polarization is demonstrated, leading to a stable ferromagnetic order confirmed for simple and superstructure cells. Specifically structural relaxation of C2O in 2D AlB2-type structure shows that the hexagonal crystal symmetry is maintained with a large c/a ratio letting magnetization develop on oxygen p valence states. Band-like O-p(x,y) and localized-like O-p(z) spin projected density of states show striking resemblance with Cr-d in well known room temperature CrO2 ferromagnet with band gap opening in majority spin states leading to an integer magnetic moment of 2 mu(B) and a strongly ferromagnetic behavior in the ground state. (C) 2017 Elsevier B.V. All rights reserved.