The coexistence of Dirac points and van Hove singularities (VHSs) near the Fermi level provides a promising mechanism for realizing high-temperature superconductivity and nontrivial topology in 2D systems. Here, via global structural searches, we identify four stable Ta-S monolayers: ${\text{Ta}}_2{\text{S}}_3$, TaS, ${\text{Ta}}_3{\text{S}}_2$, and ${\text{Ta}}_2\text{S}$. All four phases exhibit superconductivity ($T_c$ of 3.091 K, 4.194 K, 5.799 K, and 3.731 K, respectively) driven by VHS-enhanced density of states and Dirac dispersions. Notably, in the three Ta-rich systems (TaS, ${\text{Ta}}_3{\text{S}}_2$, and ${\text{Ta}}_2\text{S}$) where $Ta\ge 50\%$, robust spin-orbit coupling induces a continuous band gap with a nontrivial $Z_2=1$ invariant. The internal coupling between superconductivity and topological edge states in these phases facilitates 1D topological superconductivity via the self-proximity effect, providing a versatile platform for exploring Majorana zero modes in 2D limit.

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• Electronic structure
• Electronic structure of atoms & molecules
• Spin-orbit coupling
• Superconductivity
• Topological materials
• First-principles calculations