Thorium heptaphosphide is a binary inorganic compound of thorium metal and phosphorus with the chemical formula ThP₇. This is the most phosphorus-rich binary compound of a tetravalent thorium.

Thorium heptaphosphide can be synthesized from the elements with addition of iodine at 830 K.

Thorium heptaphosphide forms black rod-shaped crystals of orthorhombic crystal system. It decomposes to Th₂P₁₁ at 650 K in vacuo.