In this report, we present a facile, efficient, and green strategy for the preparation of fluorescent carbon quantum dots (CQDs) for bioimaging applications. To obtain CQDs, a hydrothermal carbonization approach was applied with Aloe cameronii leaves as the carbon source. The synthesized carbon exhibits significant advantages due to its high fluorescence emission, high aqueous solubility, stability, and nontoxicity. The as-prepared CQDs were characterized using TEM, UV-visible and FT-IR spectroscopy, P-XRD, and EDX. The obtained fluorescent CQDs are spherical in form and size, measuring approximately 10–20 nm. Green-synthesized CQDs have biocompatible and environmentally beneficial properties, and these CQDs are derived from natural materials. ROS, such as hydroxyl radicals, are highly reactive and play a key role in inducing oxidative stress during pathological processes. However, CQDs have the ability to scavenge reactive oxygen species (ROS) and free radicals, such as DPPH. Furthermore, the DPPH free-radical scavenging assay showed that the synthesized CQDs have significant antioxidant qualities, with IC₅₀ values of 30.53 and 57.52 μg ml⁻¹. For CQDs, the corresponding cell viability percentage was 80.76 ± 0.0099%. Additionally, at a higher dose of 100 μg ml⁻¹, the proportion of cells that survived fell to 21.91 ± 0.0077%. A study of the cell viability in the presence of CQDs resulted in an IC₅₀ value of 62.75 μg ml⁻¹. An investigation of the anticancer activity of CQDs was carried out using the lung cancer A549 cell line. In this research, we synthesized CQDs and explored their antioxidant, anticancer, and bioimaging properties using an in vitro approach.