We derive the off-shell nilpotent symmetries of the two (1+1)(1+1)-dimensional (2D) non-Abelian 1-form gauge theory by using the theoretical techniques of the geometrical superfield approach to Becchi–Rouet–Stora–Tyutin (BRST) formalism. For this purpose, we exploit the augmented version of superfield approach (AVSA) and derive theoretically useful nilpotent (anti-)BRST, (anti-)co-BRST symmetries and Curci–Ferrari (CF)-type restrictions for the self-interacting 2D non-Abelian 1-form gauge theory (where there is no interaction with matter fields). The derivation of the (anti-)co-BRST symmetries and all possible CF-type restrictions are completely novel results within the framework of AVSA to BRST formalism where the ordinary 2D non-Abelian theory is generalized onto an appropriately chosen (2,2)(2,2)-dimensional supermanifold. The latter is parametrized by the superspace coordinates ZM=(xμ,𝜃,̄𝜃)ZM=(xμ,θ,ˉθ) where xμ (with μ=0,1) are the bosonic coordinates and a pair of Grassmannian variables (𝜃,̄𝜃) obey the relationships: 𝜃2=̄𝜃2=0, 𝜃̄𝜃+̄𝜃𝜃=0. The topological nature of our 2D theory allows the existence of a tower of CF-type restrictions.