Hypochlorite ions (ClO-) are widely used in bleaching agents and disinfectants. However, high concentrations of chloride species are harmful to human health. Therefore, effective methods for the detection of ClO- ions are required. In this study, using 4-fluorophthalic acid and glycine, nitrogen-fluorine co-doped carbon nanodots (N,F-CDs) were synthesized by one-pot hydrothermal synthesis for use as a fluorescent probe for the fluorometric detection of ClO- in aqueous media, based on the inhibition of n → π* transitions. The excitation and emission peak centers of the N,F-CDs are at 387 and 545 nm, respectively. The N,F-CDs show a fast quenching response (<1 min) for ClO- and can be used in a wide pH range (pH 4-13). Under optimal conditions, the fluorescence intensity decreased with increase in the ClO- concentration from 0 to 35 μM, and a low limit of detection (9.6 nM) was achieved. This probe possesses excellent selectivity and high sensitivity and was used to analyze standardized samples of piped water, achieving a satisfactory recovery. Thus, this nitrogen-fluorine co-doped nanodot probe is promising for the detection of pollutants.