| Frederick William | |
| Succession: | Prince of Nassau-Weilburg |
| Reign: | 28 November 1788 – 9 January 1816 |
| Predecessor: | Charles Christian |
| Successor: | William |
| House: | Nassau-Welburg |
| Father: | Charles Christian, Prince of Nassau-Weilburg |
| Mother: | Princess Carolina of Orange-Nassau |
| Issue: | William, Duke of Nassau Princess Auguste Archduchess Henrietta, Duchess of Teschen Prince Friedrich Wilhelm |
| Birth Place: | The Hague |
| Death Place: | Weilburg |
Frederick William, Prince of Nassau-Weilburg (Friedrich Wilhelm, 25 October 1768, The Hague – 9 January 1816, Weilburg) was a ruler of Nassau-Weilburg. He was created Prince of Nassau and reigned jointly with his cousin, Prince Frederick Augustus of Nassau-Usingen, who became Duke of Nassau. Frederick William died in January 1816, only two months before his cousin. Both men were succeeded by Frederick William's son, William.
Frederick William was the eldest surviving son of Karl Christian of Nassau-Weilburg and Princess Wilhelmine Carolina of Orange-Nassau.
Wilhelmine Carolina was a daughter of William IV, Prince of Orange and Anne, Princess Royal and Princess of Orange. Anne was in turn the eldest daughter of George II of Great Britain and Caroline of Ansbach.
On 31 July 1788 in Hachenburg, Frederick William married Burgravine Louise Isabelle of Kirchberg (Hachenburg, 19 April 1772 – Vienna, 6 January 1827). The groom was almost twenty years old and the bride only sixteen. At the time he was still the heir to the principality. His father died on 28 November of the same year and Frederick William succeeded him.
Frederick William and Louise Isabelle had four children: