In this paper, we study a two-species chemotaxis Navier–Stokes system with Lotka–Volterra competitive kinetics: \(n_t+u\cdot \nabla n=\Delta n-\chi _1\nabla \cdot (n\nabla w)+n(\lambda _1-\mu _1n^{\theta -1}-a_1v)\) ; \(v_t+u\cdot \nabla v=\Delta v-\chi _2\nabla \cdot (v\nabla w)+v(\lambda _2-\mu _2v-a_2n)\) ; \(w_t+u\cdot \nabla w=\Delta w-w+n+v\) ; \(u_t+\kappa (u\cdot \nabla )u=\Delta u+\nabla P+(n+v)\nabla \phi \) ; \(\nabla \cdot u=0\) , \(x\in \Omega \) , \(t>0\) in a bounded and smooth domain \(\Omega \subset \mathbb {R}^3\) with no-flux/Dirichlet boundary conditions, where \(\chi _1, \chi _2\) are positive constants. We present the global existence of generalized solution to a two-species chemotaxis Navier–Stokes system.