This paper introduces a novel hybrid joining technology for thermoplastic-to-thermoplastic composite parts, combining ultrasonic welding (UW) and friction drilling fasteners (FDFs) to create strong, durable joints. Currently, there is no rapid, robust method available for reliably joining thermoplastic composite parts, especially for applications requiring high joint integrity. The proposed hybrid method addresses this challenge by integrating the advantages of both UW and FDFs. This approach not only enables fast, low-cost fabrication but also enhances bonding integrity and overall joint strength. A high-fidelity performance model is developed to understand the failure modes of the hybrid joint, providing valuable insights into factors such as bolt arrangement and load distribution. This model aids in optimizing the joint design for maximum performance. Performance data are gathered from single-lap joints fabricated using UW, FDF, and the combined UW-FDF method, which are tested under static loading conditions. The results are compared to baseline performance data from autoclave-fabricated joints, highlighting the advantages and effectiveness of the hybrid joining approach in terms of strength, durability, and cost-efficiency. © 2025, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.