The transportation industry has been facing stringent environmental regulations to decrease fuel consumption and CO2 emissions. A promising solution to fulfill these demands is decreasing the structural weight of vehicles and airplanes by combining lightweight alloys and fiber-reinforced polymers in hybrid structures. Conventional joining technologies are usually inadequate to produce high performance joints. To overcome these limitations, advanced joining technologies are under development such as: Friction Spot Joining (FSpJ), Friction Riveting (FricRiveting) and Ultrasonic Joining (U-Joining). This master dissertation was devised to evaluate FSp, FricRiveting and U-Joining joints produced with different heat input levels (low and high) in terms of process temperature development, microstructural features, quasi-static mechanical performance and the respective failure mechanisms. In this context, microscopy techniques (i.e. optical, confocal laser and scanning electron), X-Ray micro-computed tomography (microCT), lap shear and T-Pull testing were chosen for this purpose. FSp joints produced under HHI joining condition achieved an ultimate lap shear force (ULSF) 43 percent higher than LHI joints, whereas HEI joints produced by FricRiveting process achieved ultimate tensile force (UTF) 46 percent higher than LEI joints. The lap shear strength of ultrasonically joined joints produced under HEI joining condition was up to 85 percent higher than LEI joints. FSp joints failured in the center of the overlap area while friction-riveted joints failured through the rivet (HEI) and full rivet pull-out (LEI). Ultrasonically joined joints failured through the polymer (HEI), whereas LEI joints failured through a combination of shearing of the metallic pins and a mixed cohesive (CF) and adhesive (AF) failure.