Lakshmana Sena or Lakshman Sen (Bengali: লক্ষণ সেন; reign: 1178–1206) was the ruler from the Sena dynasty of the Bengal region on the Indian subcontinent. His rule lasted for 28 years.

Lakshmana Sena succeeded his father Ballala Sena. ^[1]The history of his reign can be reconstructed from the epigraphs of his time that include the Deopara Prashasti stone inscriptions and copper plates from his successors. Tabaqt-i-Nasiri, composed by 1260, is another source of information about his reign.

In his youth, Lakshmana Sena led military campaigns against Gauḍa, Kamarupa, Kalinga and Varanasi (under the rule of Gahadavala King Jayachandra), and helped his grandfather Vijaya Sena and father Ballala Sena to expand the borders of the Sena kingdom. However, he ascended to the throne of Bengal himself at an advanced age.

Lakshmana Sena was interested in literature and composed a number of Sanskrit poems. He completed Adbhuta Sagara, a book incompletely written by his father. He assembled some of the major figures in contemporary Sanskrit literature-- Jayadeva, Dhoyin and Sharan—as his court poets. Among his other courtiers, Sridharadasa, Halayudh Mishra and Umapati Dhara also produced important treatises and works of literature.^[2] Lakshman Sena established a calendar era called Lakshmana Era that was used in Bengal and Bihar for at least 400 years.^[3][4] He also founded the prominent medieval city of Lakhnauti.^[4]

He was a devoted Vaishnav and took up titles like Paramavaisnava or Paramanarasingha to reflect that.^[2] Lakshmansena's generosity even attracted the attention of Minhaj-us-Siraj, the author of the TABAQAT-I-NASIRI, who designated him as a 'great Rae' of Bengal and compared him with Sultan Qutubuddin.^[2]

After subjugating Bihar in 1200,^[5] Turko-Afghan invader Bakhtiyar Khaliji's forces entered Nabadwip in Bengal. Subsequently, Bakhtiyar went on to capture the capital and the principal city, Lakhnauti.^[6]

Bakhtiyar marched against Bengal with a band of well-trained horsemen.^[2] He was at first treated in Nadia as a horse-dealer.^[2] At that time Lakshmansena was an octogenarian.^[2] The old Sena king, who was then at his dinner, was completely taken by surprise.^[2] When Bakhtiyar captured Nadia, Lakshmansena withdrew to southeastern Bengal, where his sons continued the rule of Senas for the some time.^[2] The detailed account of this invasion is given in Tabaqat-i-Nasiri.^[7] However the laudatory verse of Sarana refers to Lakshmanasena's victory against a Mlechchha king, who may be regarded as a Muslim ruler in Bengal.^[8]

• List of rulers of Bengal