This study introduces a novel strategy to toughen hydrogels using fibrillar connected double networks (fc-DN), which consist of a polyacrylamide (PAAm) network chemically crosslinked by an acrylated agarose (AcAG) fibril network. The fc-DN design enables efficient stress transfer between the two networks and high fibril alignment during deformation, leading to high strength and toughness while maintaining low plastic deformation. The fc-DN hydrogel achieves an ultimate tensile strength of 8 MPa and a toughness of over 55 MJ m⁻³, which is 3 and 3.5 times higher than that of conventional fibrillar double network hydrogels. The fc-DN hydrogel is demonstrated as a load-bearing damping material for a jointed robotic lander, showing improved mechanical properties compared to conventional f-DN hydrogels. The fc-DN design provides a new toughening mechanism for hydrogels, with potential applications in soft robotics and bioelectronics. The fc-DN hydrogel is prepared by crosslinking AcAG fibrils with PAAm, resulting in an interconnected interpenetrating network. The mechanical properties of the fc-DN hydrogel can be tuned by adjusting the chemical composition and crosslink density. The fc-DN hydrogel exhibits low residual strain after high tensile strain, indicating its ability to withstand large deformations without permanent damage. The toughening mechanism of the fc-DN hydrogel is attributed to the combination of high fracture strain, strength, and energy dissipation through the pull-out of agarose chains and alignment of fibrils. The fc-DN hydrogel is demonstrated as a load-bearing component in soft devices, showing improved performance compared to conventional f-DN hydrogels. The study highlights the potential of fc-DN hydrogels for applications requiring high mechanical strength and toughness with low plastic deformation.This study introduces a novel strategy to toughen hydrogels using fibrillar connected double networks (fc-DN), which consist of a polyacrylamide (PAAm) network chemically crosslinked by an acrylated agarose (AcAG) fibril network. The fc-DN design enables efficient stress transfer between the two networks and high fibril alignment during deformation, leading to high strength and toughness while maintaining low plastic deformation. The fc-DN hydrogel achieves an ultimate tensile strength of 8 MPa and a toughness of over 55 MJ m⁻³, which is 3 and 3.5 times higher than that of conventional fibrillar double network hydrogels. The fc-DN hydrogel is demonstrated as a load-bearing damping material for a jointed robotic lander, showing improved mechanical properties compared to conventional f-DN hydrogels. The fc-DN design provides a new toughening mechanism for hydrogels, with potential applications in soft robotics and bioelectronics. The fc-DN hydrogel is prepared by crosslinking AcAG fibrils with PAAm, resulting in an interconnected interpenetrating network. The mechanical properties of the fc-DN hydrogel can be tuned by adjusting the chemical composition and crosslink density. The fc-DN hydrogel exhibits low residual strain after high tensile strain, indicating its ability to withstand large deformations without permanent damage. The toughening mechanism of the fc-DN hydrogel is attributed to the combination of high fracture strain, strength, and energy dissipation through the pull-out of agarose chains and alignment of fibrils. The fc-DN hydrogel is demonstrated as a load-bearing component in soft devices, showing improved performance compared to conventional f-DN hydrogels. The study highlights the potential of fc-DN hydrogels for applications requiring high mechanical strength and toughness with low plastic deformation.