Frederick (c. 1357 – 5 June 1400), a member of the House of Welf, was Duke of Brunswick-Lüneburg and ruling Prince of Brunswick-Wolfenbüttel from 1373 until his death. In May 1400, he unsuccessfully stood as a candidate for the election as German king-elect at Frankfurt, in opposition to Wenceslaus of Luxembourg, and was murdered on his way home.