Lieutenant-General Lionel Protip "Bogey" Sen, DSO (20 October 1910 – 17 September 1981) was a decorated Indian Army general.

[4] He was formally appointed to the Indian Army as an officer with the 10th Baluch Regiment on 26 October 1932 (seniority from 29 January 1931).

In early 1945, his battalion took a prominent role in the Battle of Hill 170, during which he was awarded the Distinguished Service Order (DSO).

[8] The citation recommending Sen for the DSO (which was not published) noted:[2] ...In spite of the greatest difficulties Lt-Col Sen held firmly on to his precarious positions, and the final success of the whole operation was in no small measure due to his dashing assault and tenacious defence.

During the Indo-Pakistani War of 1947–1948, he was promoted to acting brigadier and commanded the 161st Indian Infantry Brigade, and ordered to take over the defence of Srinagar and the Kashmir Valley, for which he received a mention in dispatches.