| Christian Ulrich I, Duke of Württemberg-Oels | |
| Noble Family: | House of Württemberg |
| Father: | Silvius I Nimrod, Duke of Württemberg-Oels |
| Mother: | Elisabeth Marie, Duchess of Oels |
| Spouse: | Anna Elisabeth of Anhalt-Bernburg Sibylle Maria of Saxe-Merseburg Sophie Wilhelmine of East Frisia Sophia of Mecklenburg-Güstrow |
| Birth Place: | Oels Castle in Oels |
| Death Place: | Oels Castle in Oels |
Duke Christian Ulrich I of Württemberg-Oels (9 April 1652, at Oels Castle in Oels – 5 April 1704, in Oels Castle) was a German nobleman. He was the ruling Duke of Württemberg-Bernstadt from 1669 to 1697 and then the ruling Duke of Oels-Württemberg from 1697 until his death.
Christian Ulrich I was the third son of Duke Silvius I Nimrod of Württemberg-Oels from his marriage with Duchess Elisabeth Marie, a daughter of Duke Charles Frederick I Poděbrady, Duke of Oels and Anne Sophie of Saxe-Weimar.
When his oldest brother Charles Ferdinand died in 1669, Christian Ulrich inherited the Duchy of Bernstadt.
When his older brother Silvius II Frederick died in 1697, Christian Ulrich inherited the Duchy of Oels, Christian Ulrich kept the Duchies of Oels and Dobroszyce with Międzybórz and parts of Trebnitz and transferred Bernstadt to his nephew Charles.
In 1698, Christian Ulrich built a ducal crypt as an extension of Castle Church of St. John. He began a significant collection of books and art at Oels Castle. In 1685, he purchased the town of Neudorf from Balthasar Wilhelm von Prittwitz, Lord of Rastelwitz. Between 1685 and 1692, he constructed a baroque castle at Neudorf, which he named Sibyllenort, after his second wife, Marie Sibylle of Saxe-Merseburg.
He died on 5 April 1704, aged 51, at Oels Castle and was buried in the ducal crypt he had built.
He completed his first marriage, on 13 March 1672 in Bernburg with Anna Elisabeth of Anhalt-Bernburg, daughter of Prince Christian II of Anhalt-Bernburg and Eleonora Sophia of Schleswig-Holstein Sonderburg. With her he had seven children:
He completed his second marriage, on 27 October 1683 in Doberlug with Sibylle Maria (born: 28 October 1667; died: 9 October 1693), daughter of Duke Christian I of Saxe-Merseburg and Christiana of Schleswig-Holstein-Sonderburg-Glücksburg. With her he had seven more children:
He concluded his third marriage, on 4 February 1695 in Hamburg with Sophie Wilhelmine of East Frisia (born: 17 October 1659; died: 4 February 1698), daughter of Prince Enno Louis Cirksena of East Frisia and Juliana Sophia Justina of Barby-Mühlingen. With her he had one daughter:
He concluded his fourth marriage, on 6 December 1700 in Güstrow with Sophia (born: 21 June 1662; died: 1 June 1738), a daughter of Duke Gustav Adolph of Mecklenburg-Güstrow and Magdalene Sibylle of Schleswig-Holstein-Gottorp. This marriage remained childless.