The simple Regression toolbox, simpleR, contains a set of functions in Matlab to illustrate the capabilities of several statistical regression algorithms. simpleR contains simple educational code for linear regression (LR), decision trees (TREE), neural networks (NN), support vector regression (SVR), kernel ridge regression (KRR), Gaussian Process Regression (GPR), and Variational Heteroscedastic Gaussian Process Regression (VHGPR). A dataset of spectra and associated chlorophyll content is included to illustrate training/testing procedures.