With the aim of selective bioimaging of cancer cells, we synthesized and characterized an indomethacin-conjugated fluorescence probe, IQ-1. The probe IQ-1 was non-cytotoxic, and using confocal fluorescence microscopy we observed that its fluorescence intensity in various human cells depended on the COX-2 levels. Compared with normal cell lines (RAW 246.7 and fibroblast cells), the probe showed an increased fluorescence in cancer cells (OVCAR 3, HepG2, and HeLa cells) where COX-2 is overexpressed. LPS-treated inflamed cell lines (RAW 264.7 cells and fibroblast cells) with high COX-2 levels also showed enhanced fluorescence. On the other hand, upon co-treatment with a COX-2 inhibitor such as indomethacin or aceclofenac, the fluorescence intensity of IQ-1 in HeLa cells was decreased. From these results, we confirm that the newly synthesized IQ-1 has a remarkable targetability towards cancer cells over normal cells with respect to the COX-2 levels, and can be used as a selective bioimaging agent for cancer cells. Therefore, IQ-1 could be structurally modified for use as a cancer-labelling tool with improved cellular uptake, which is crucial for efficient diagnosis and therapeutic monitoring in precision medicine as part of standard patient care.