Vyacheslav Ivanovich Lebedev (Russian: Вячеслав Иванович Лебедев) (January 27, 1930 – March 22, 2010) was a Soviet and Russian mathematician, known for his work on numerical analysis.

He authored over a hundred papers and several books, most noticeably "Numerical methods in the theory of neutron transport" jointly with Gury Marchuk and "Functional Analysis in Computational Mathematics," based on his lectures.

Lebedev quadrature has become one of the popular methods of integration on a sphere.

He worked in many areas of computational and applied mathematics, ranging from software development for nuclear reactors modeling to approximation by polynomials, from quadrature on a sphere to numerical solution of stiff for which he developed explicit Chebyshev methods called DUMKA, systems of PDEs, from domain decomposition and Poincaré–Steklov operators to Finite difference methods, from iterative solvers to parallel computing.

He was a recipient of the Soviet State Award for developing mathematical methods of particle transport theory in 1987 and Chebyshev Gold medal (Russian: ru:Золотая медаль имени П. Л. Чебышева) in 2002–03.