Space-Time Projection (STP) is introduced as a data-driven forecasting approach for high-dimensional and time-resolved data.STP computes extended space-time proper orthogonal modes from training data to generate forecasts by projecting these modes onto new data.The method relies on the orthogonality and optimal correlation of the modes, and no additional hyperparameters are required.Comparative studies with LSTM neural networks showed that STP consistently provided more accurate forecasts.