The focus of the work described in this paper is on the development of a practical Drucker-Prager (DP) type constitutive model for the nonlinear finite-element analysis (NLFEA) of fiber-reinforced polymers (FRP)-confined masonry columns under concentric compression. This paper introduces analytical relations for the cohesion and internal friction angle for masonry constituents, i.e., solid clay bricks and mortar. The proposed relations account for the slight change of the linear part of the compressive meridian into a curve at higher hydrostatic pressure values and predict the compressive and tension meridians of concrete even for high hydrostatic pressure. Evaluating possible failure criteria in FRP-confined masonry columns, 14 test specimens from three major experimental studies are successively modeled through the proposed approach. The results of NLFEA show both satisfactory predictions of the stress-strain response of the columns and theoretical understanding for the strain distributions in the FRP sheets. DOI: 10.1061/(ASCE)CC.1943-5614.0000268. (C) 2012 American Society of Civil Engineers.