Reactive Powder Concrete (RPC) is a part of an ultra-high-strength concrete family. It has a dense matrix due to a very low water-cement ratio, which increases its brittleness. Therefore, RPC is produced with a high volume of fiber reinforcement to attain ductility and fire resistance. Unfortunately, new fibers are expensive and yield a high carbon footprint. The rise in the cost and carbon footprint of fiber-reinforced RPC can be controlled by using Recycled Steel Fibers (RSF) derived from scrap tyres. In this study experimental campaign is conducted to compare the mechanical performance of RPC with new steel fiber (NSF) and RSF. Performance of NSF and RSF is compared at 0%, 1%, 2%, 3% and 4% volume fractions. The studied properties are bond strength, compressive strength (CS), splitting-tensile strength (STS), flexural strength (FS), and ultrasonic pulse velocity (UPV). Testing results showed that 3% RSF improves the CS, STS, and FS of plain-RPC by 9%, 23% and 58%, respectively. RSF-RPC performs around 90% potential of equivalent NSF-RPC in all mechanical properties at the same volume of fiber. RSF has implications for a cheap and eco-friendly substitute for NSF. The optimum dosage of NSF and RSF is 2% considering maximum mechanical strength without a significant increase of the self-load.