To identify the activated tyrosine kinase signaling pathways in HNSCC, we carried out phosphotyrosine profiling using a panel of HNSCC cell lines compared to a normal oral keratinocyte. A total of 61 unique phosphosites were identified across these cell lines. Dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A) was one of the kinases hyperphosphorylated at Y321 in all the HNSCC cell lines compared to the normal oral cell line OKF6/TERT1. Inhibition of DYRK1A using its specific siRNA and inhibitor resulted in a decrease in the invasion and colony formation ability of the HNSCC cell lines. Further, the treatment of mice bearing HNSCC xenograft tumors with DYRK1A inhibitor (harmine) showed regression of tumor growth. Our results demonstrate that DYRK1A could be a novel therapeutic target in HNSCC.