Benedek was born in Sopron as the son of a physician. He was trained at the Theresiana Military Academy in Wiener Neustadt, from which he graduated seventh in his class. In 1822, he was assigned to the 27th infantry regiment of the Austrian Imperial Army. He was made a first lieutenant in 1833, and was assigned to the Quartermaster-General. In 1835, he was promoted to the rank of captain.
In 1840 Benedek was made a major and aide to the General Commander of Galicia. While still serving in Galicia he was again promoted to lieutenant-colonel in 1843. For suppressing an uprising in the town of Gdow in 1846 he was awarded the Knight's Cross of the Order of Leopold as well as given the rank of colonel.
Commander in Italy
In August 1847, Benedek was entrusted with the command of the 33rd infantry regiment in Italy. On 5 April 1848 he took over the command of a newly formed brigade that consisted of two battalions. This brigade saw battle in the first Italian war of independence several times, notably at Curtatone in 1848. The following day, Benedek led his troops in the Battle of Goito.
Benedek was afterwards awarded the Commanders' Cross of the Order of Leopold, and the Knight's Cross of the Military Order of Maria Theresa. This officially made Benedek a knight (hence Ludwig, Ritter von Benedek). On April 3, 1849, he became major general and was appointed to the staff of the Chief of Quartermaster-General with the 2nd Army in Italy.