This review discusses recent progress in 2D gravity coupled to conformal matter with dimensions less than one, using random matrix representations. It covers the saddle-point approximation for these models, including related $O(n)$ matrix models. For $d < 1$ matter, the matrix problem can be solved using orthogonal polynomials in many cases. Alternatively, in the continuum limit, the orthogonal polynomial method is equivalent to constructing representations of the canonical commutation relations using differential operators. For pure gravity or discrete Ising-like matter, the sum over topologies reduces to solving nonlinear differential equations (the Painlevé equation for pure gravity). In pure gravity and unitary models, perturbation theory is not Borel summable, so it does not define a unique solution. The review also covers the computation of correlation functions directly in the continuum formulation of matter coupled to 2D gravity and compares these results with matrix model outcomes. Finally, it reviews the relationship between matrix models and topological gravity, as well as the connection to intersection theory of the moduli space of punctured Riemann surfaces.This review discusses recent progress in 2D gravity coupled to conformal matter with dimensions less than one, using random matrix representations. It covers the saddle-point approximation for these models, including related $O(n)$ matrix models. For $d < 1$ matter, the matrix problem can be solved using orthogonal polynomials in many cases. Alternatively, in the continuum limit, the orthogonal polynomial method is equivalent to constructing representations of the canonical commutation relations using differential operators. For pure gravity or discrete Ising-like matter, the sum over topologies reduces to solving nonlinear differential equations (the Painlevé equation for pure gravity). In pure gravity and unitary models, perturbation theory is not Borel summable, so it does not define a unique solution. The review also covers the computation of correlation functions directly in the continuum formulation of matter coupled to 2D gravity and compares these results with matrix model outcomes. Finally, it reviews the relationship between matrix models and topological gravity, as well as the connection to intersection theory of the moduli space of punctured Riemann surfaces.