Louis Rudolph (German: Ludwig Rudolf; 22 July 1671 – 1 March 1735), a member of the House of Welf, was Duke of Brunswick-Lüneburg and ruling Prince of Wolfenbüttel from 1731 until his death.

Louis Rudolph was the maternal grandfather of Empress Maria Theresa, Emperor Peter II of Russia and Charles I, Duke of Brunswick-Wolfenbüttel.

He became a major general in the service of the Habsburg emperor Leopold I in 1690 and was promptly captured in the Battle of Fleurus by the forces of King Louis XIV of France.

After being released the same year, his father gave him the Brunswick County of Blankenburg as a present, with the consent of his eldest son Augustus William, insofar violating the primogeniture principle laid down by the late Duke Henry V. When in 1707 Prince Anthony Ulrich managed to betroth Louis Rudolph's daughter Elisabeth Christine to the Habsburg archduke Charles VI, his elder brother Emperor Joseph I raised the County of Blankenburg to an immediate principality.

In particular, with the exception of Albert II, Prince of Monaco, Louis Rudolph is an ancestor of all current sovereigns of hereditary European monarchies.