A foldable solar energy collector has a base and a panel body. The base has an elevatable telescopic shaft mounted thereon. The panel body has a bottom board and multiple side panels pivotally mounted around a perimeter of the bottom board. Two foldable panels are respectively and pivotally mounted on two edges of each side panel. A link assembly is pivotally mounted between the panel body and the telescopic shaft and has multiple inside and outside links pivotally connected to each other. One end of each inside link away from a corresponding outside link is pivotally mounted on the telescopic shaft. One end of each outside link away from a corresponding inside link is pivotally mounted between adjacent two of the foldable panels. When the telescopic shaft is elevated, the link assembly is pulled to drive the panel body to unfold or fold, rendering convenience in operation and storage.