Ajit Singh or Raja Ajit Singh Bahadur (16 October 1861 – 18 January 1901) was a ruler of Shekhawat dynasty of the Indian princely state of Khetri, Rajasthan between 1870 and 1901. He was born on 16 October 1861 in Alsisar, India. His father was Thakur Chattu Singh, a resident of Alsisar. Ajit Singh was later adopted to Khetri and after the death of Fateh Singh, he became the eighth king of Khetri in 1870. In 1876, he married Rani Champawatiji Sahiba and the couple had one son and two daughters. He died on 18 January 1901 at Sikandra, and was cremated at Mathura.