Tetracycline (TC) is among the most commonly used antibiotics on the market today. As a result, huge amounts of TC-contaminated water enter the aquatic environment. This drug is considered an emerging pollutant and can cause acute problems for flora and fauna. Therefore, an efficient adsorbent is needed to remove TC from water bodies. Plant-based biochar can be a promising way to remove TC from water. In this work, a biochar (PLB) is made from dead palm leaves (PL), as a novel, eco-friendly, and effective adsorbent. The surface morphology and structural properties of the prepared adsorbent were confirmed by different characterization techniques. The results confirmed that the PLB has a higher surface area and more mesoporous hierarchical structure compared to raw PL. TC Adsorption experiments were carried out under different environmental conditions including contact time, solution pH, initial concentration of TC, adsorbent dose, and temperature. The adsorption kinetics data corroborated a pseudo-second order (PSO) model while the monolayer uptake capacity was found to be 13.71 mg/g and 6.52 mg/g for PLB and PL, respectively. The adsorption process was spontaneous and endo-thermic. The adsorbent exhibited regeneration capabilities for at least three consecutive cycles. The H-bonding, 7C-7C interaction, electrostatic interaction, and pore-filling played a dominant role in TC adsorption. According to the study’s findings, inexpensive biochar adsorbent is effective at removing TC and may also be used to potentially remove other toxins from vast amounts of wastewater samples.