This article focuses on the fabrication and mechanical characterization of dissimilar tailor-welded blanks produced from two advanced high-strength steels with a minimum ultimate tensile strength of 980 MPa.Sheets of DP980 and TRIP980 steels with thicknesses of 2 mm and 1.8 mm, respectively, were joined by fiber laser butt welding. The primary process variables affecting joint quality including laser power, welding speed and pulse frequency were systematically investigated using a Taguchi L9 orthogonal array to optimize joint performance. Joint acceptability was established based on the requirement that neither crack initiation nor separation occur within the fusion or heat-affected zone; failure had to initiate in the base material under biaxial loading. Once the optimal welding parameters had been established, selected tailor welded blanks were further characterized through a series of mechanical and microstructural evaluations, including uniaxial tensile testing, microhardness measurments and optical metallographic analysis. The results demonstrated that the parameter combination of 1.5 kW, 18 mm/s, and 18 Hz produced the highest joint quality. The weld zone showed increased hardness, and tensile fracture occurred in the TRIP sheet, demonstrating that the weld region possessed higher strength than the base metals.