Palabos-npFEM is a computational framework for the simulation of cellular blood flow. The software resolves the trajectories and deformed state of blood cells, such as red blood cells and platelets, and the complex interaction between them. The tool combines the lattice Boltzmann solver Palabos for the simulation of blood plasma (fluid phase), a finite element method (FEM) solver for the resolution of blood cells (solid phase), and an immersed boundary method for the coupling of the two phases. Palabos-npFEM provides (except for a CPU-only version) the option to simulate the deformable bodies on GPUs, thus the code is tailored for the fastest supercomputers. The software is integrated in the Palabos core library (https://gitlab.com/unigespc/palabos), it offers the possibility to simulate various setups, e.g. various geometries, blood parameters, and it can readily use alternative solvers for the resolution of the various phases given its modular nature.