Lehna Singh Majithia (died 1854), also romanized as Lahina or Lahna, was a polymath, inventor, warrior, and statesman.

[1][2] He had an interest in statecraft, architecture, mathematics, astronomy, firearms, mechanics, languages, art, and ordnance.

[3] Lehna assisted general Claude Auguste Court on constructing cannons based on European models.

He designed a mechanism resembling a clock, showing the hour, the date, the day of the week and the phases of moon and other constellations.

[5] He had been awarded the titles of Kasir-ul-Iktidar ('Chief of Exalted Dignity') and Hasam-udaula ('the Sword of the State') by Ranjit Singh.