Background/Objectives: Delonix regia seeds contain phytochemicals with therapeutic potential, but their activity against Helicobacter pylori and biomedical properties remain incompletely characterized. This study aimed to characterize the phenolic and amino acid composition of D. regia seed extract (DRSE) and evaluate its anticancer, wound-healing, anti-inflammatory, anticoagulant, antibacterial, antibiofilm and urease-targeted docking activities. Methods: DRSE was analyzed by high-performance liquid chromatography (HPLC) and amino acid analysis. Biological effects were assessed using MTT cytotoxicity, scratch wound-healing, bovine serum albumin (BSA) denaturation, prothrombin time (PT) and partial thromboplastin time (PTT), antibacterial and crystal violet antibiofilm assays. Gallic acid and vanillin were docked against H. pylori urease (PDB ID: 1E9Y). Results: Gallic acid was the predominant phenolic compound (1417.90 µg/g), while aspartic and glutamic acids dominated the amino acid fraction. DRSE showed preferential cytotoxicity toward A431 carcinoma cells (IC₅₀ = 108.97 ± 0.68 µg/mL) compared with HFB4 fibroblasts (IC₅₀ = 318.56 ± 2.06 µg/mL), yielding a selectivity index of 2.92. Scratch closure was comparable to the control (81.71% versus 80.85%), although the migration rate increased to 16.12 µm. DRSE inhibited protein denaturation by 91.20% (IC₅₀ = 6.39 ± 0.19 µg/mL) and prolonged PT and PTT to 27.37 and 90.50 s, respectively. It inhibited H. pylori with minimum inhibitory and bactericidal concentrations of 31.25 µg/mL and suppressed biofilm formation by 95.39%. Gallic acid and vanillin showed comparable urease docking scores of −4.72 and −4.71 kcal/mol. Conclusions: DRSE showed selective anticancer, anti-H. pylori, antibiofilm, anti-inflammatory, anticoagulant, and moderate pro-migratory activities. Mechanistic, safety and in vivo studies are warranted.