Ottilie was born before or on 18 April 1437, possibly in
Breda, as the only daughter of
Count Henry II of Nassau-Siegen and his first wife Countess Genoveva of Virneburg. Ottilie married in 1449/1450 to Count
Philip the Younger of Katzenelnbogen (1427), the eldest son of Count
Philip the Elder of Katzenelnbogen and his first wife Countess Anne of Württemberg. This led to a conflict with her paternal uncle Count
John IV of Nassau-Siegen, who had succeeded his brother in all his possessions and was granted the County of Diez as a fief by
Archbishop of
Trier on 4 November 1451. The conflict was complicated further due to the fact that another part of the County of Diez belonged to Ottilie's father-in-law Philip the Elder of Katzenelnbogen. Ottilie remarried on 3 June 1475 to Count
Oswald I of Tierstein ( – before 1488). Oswald was
governor in the
Alsace, the
Sundgau and the
Breisgau and councillor in
Lorraine and the
Electorate of Cologne. Ottilie's daughter,
Ottilie of Katzenelnbogen, however, also immediately laid claim to the
County of Katzenelnbogen. On 6 May 1482 Ottilie of Katzenelnbogen renounced her claims to the counties Katzenelbogen and Diez ==Issue==