<p>This paper presents a compact and efficient MATLAB implementation for the three-dimensional topology optimization of continuous fiber-reinforced composite (CFRC) structures with spatially varying fiber orientations and fiber volume fractions. The implementation includes design variable filtering and projection/normalization, finite element analysis, sensitivity analysis, design variable update, visualization, and verification of fiber orientation optimality. The effective stiffness matrix in the global coordinate system is obtained by combining analytical micromechanics with a tensor invariant-based representation. A template stiffness matrices (TSMs)-based method is employed to efficiently compute all element stiffness matrices without Gauss quadrature. The lower triangular assembly technique is used to accelerate the computation of the global stiffness matrix. The TSMs-based method also enables efficient sensitivity analysis. The design variables are updated in a decoupled manner: the density and fiber volume fraction variables are updated simultaneously using the method of moving asymptotes (MMA), while the fiber orientation variables are updated through a separate numerical scheme in which a convex approximate subproblem is solved analytically at each iteration. Visualization of the optimized topology, spatially varying fiber volume fractions, and fiber orientations is provided. The optimality of the optimized fiber orientations is also verified. Extensions to the code are discussed. The complete code is provided in the Supplementary Material and is also available at <a href="https://github.com/qmdxcube/CFRCTop3D.">https://github.com/qmdxcube/CFRCTop3D.</a></p>