Arnold I of Laurenburg, (died before 1154), was count of Laurenburg and an ancestor of the House of Nassau.
Arnold was a son of Dudo of Laurenburg () and the fourth of the seven daughters of count Louis I of Arnstein, possibly her name was Irmgardis or Demudis.
Arnold is mentioned as count of Laurenburg between 1124 and 1148. He probably ruled together with his brother Rupert I. Arnold and Rupert built Nassau Castle around 1124.
In 1124, Arnold became the Vogt of Idstein. Idstein had come under the control of Count Dudo in 1122.
Arnold was the Vogt of St. George's Monastery in Limburg 1124âÂÂ1148.
No marriage has been mentioned of Arnold.