This study addressed the issue of recycling waste plastic bottles as recycled plastic fiber (RPF) into sustainable waste plastic fiber-reinforced concrete (WPFRC). Thus, the effects of different RPF lengths (30, 50, and 70 mm), widths (2, 4, and 6 mm), and contents (0.3, 0.45, and 0.6 vol%) on the performance of WPFRC were systematically evaluated through the laboratory test series of workability, fresh unit weight, compressive and flexural strengths, drying shrinkage, water absorption, and ultrasonic pulse velocity. Results indicated that the addition of RPF had a negligible effect on the fresh properties of the WPFRC mixtures, while significantly enhancing the load-bearing capacity and reducing drying shrinkage in the WPFRC specimens, particularly at early ages. Additionally, all WPFRC specimens exhibited low water absorption rates and high ultrasonic pulse velocities, indicating good quality and durability. Overall, the study found that an RPF content of 0.45% by volume, an RPF length of 70 mm, and an RPF width of 2 mm yielded the best performance for WPFRC. As a result, incorporating RPF into concrete fosters the development of strong, durable, and sustainable materials for green construction.