“High-performance thin-layer chromatography (HPTLC)” methods for gefitinib (GFT) estimation are scarce in the literature. In addition, greener analytical techniques for GFT estimation are also lacking in the literature. Accordingly, an attempt was undertaken to invent and validate a sensitive and greener normal-phase HPTLC method for GFT analysis in commercial tablets in comparison to the routine normal-phase HPTLC method. The greenness index for both methods was assessed using “Analytical GREENness (AGREE)” methodology. GFT detection was carried out using both methods at 332.0 nm. In the 30–700 ng/band and 20–1400 ng/band ranges, the routine and greener HPTLC assays were linear for GFT estimation. The greener HPTLC method was highly sensitive, more accurate, more precise, and more robust than the routine HPTLC assay for GFT estimation. Both methods were able to detect GFT in the presence of its degradation products, suggesting the stability-indicating property of both methods. The assay of GFT in commercial tablets was 92.45% and 99.74% using the routine and greener HPTLC assays, respectively. The AGREE index for routine and greener analytical assays was predicted to be 0.44 and 0.77, respectively, indicating the excellent greenness index of the greener HPTLC assay over the routine HPTLC assay. The greener HPTLC assay is considered superior to the routine HPTLC assay based on these results.