Abstract AlSi12Cu1Mg1–SiC-MWCNTs hybrid composite foam (HCFs) of varying relative densities (RD) were made through stir casting technique using CaH 2 as a foaming agent. Varying wt.% of SiC and multi-wall carbon nanotubes (MWCNTs) were used as reinforcing as well as thickening agents. Uniform distribution of SiC and MWCNTs in the matrix was confirmed by FESEM images and Raman analysis. It was observed that the elastic modulus (E), plastic collapse stress (σ p c), plateau stress (σ p l), and energy absorption (E a b) of HCFs increase significantly when both (MWCNTs and SiC) were added together. But, when SiC and MWCNTs added individually, the extent of improvement in these properties is relatively low. However, densification strain varies marginally with the variation in reinforcement. Irrespective of reinforcement, the σ p l, the E, and the E a b increased with increment in RD The different values also followed the existing relations, when the fraction of cell edge materials varied with RD, the deformation mechanism was understood from photographs taken during deformation.