Ghanashyam Das alias Ghanada (Bengali: ঘনাদা), the protagonist of the Ghanada series of science fiction novels written in Bengali, is a fictional character created by Premendra Mitra in 1945. In the novels, the character fights evil and stands against international terrorism. The far-fetched stories take place in multiple international locations, and across a historical timeline. He is depicted regularly outwitting his fellow boarders of the mess-bari at 72, Banamali Naskar Lane, Kolkata (Calcutta). Ghanada was a personification of Premendra Mitra's anti-fascist humanistic ideologies and moral universe. His stories were notably accurate from a historical, geographical and scientific standpoint.

Ghanada's first appearance was in a story titled Mosha (The Mosquito), published in the Puja annual Alpana (Bengali: আলপনা) in 1945 published by Deb Sahitya Kutir, Kolkata, West Bengal, India.

Ghanada was engaged by a company in Sakhalin to collect amber sometime during 1939, and in due course, he landed up to a scientific laboratory set by Mr Nishimara, an entomologist, in search of a Chinese labourer who went missing. It was later revealed that Mr. Nishamara was genetically converting the mosquitos into deadly agents of biological warfare. When the lone, genetically engineered mosquito landed on the face of Mr. Nishimara and sealed his fate by stinging him, Ghanada slapped Nishmara to kill the mosquito and eliminated a severe threat towards humanity. He declared he never intended to kill another mosquito ever after in his lifetime.

At the end of the story Ghanada took a deep breath as if he was so tired from killing that mosquito and said, "I never felt like killing a mosquito after that incident."

The character of Ghanashyam Das alias Ghanada was outlined as a bachelor, dark-complexioned male with a tall, boney and skeletal structure, aged "anywhere between thirty-five to fifty-five", as described by the author himself in Mosha- the first story of the Ghanada series. He stayed in the third-floor attic of a shared apartment called "Mess-bari" (Bengali: মেস-বাড়ি) at 72, Banamali Naskar Lane, Calcutta, West Bengal, India, along with other boarders, who called him Ghanada, while Ghana is the shortened form of his name Ghanasyam, and the term "da" is a suffix added to the name of an elder male in Bengal to convey reverence and affection. Though he was rarely found engaged in any activity or work other than telling fantastic tales to the boarders of the apartment, sitting in his armchair and cadging cigarettes from his fellow boarders, his tall tales engaged him with most of the major events that had happened in the world for last two hundred years and there was no place on earth which he didn't visit.

গত দুশো বছর ধরে পৃথিবীর হেন জায়গা নেই যেখানে তিনি যাননি, হেন ঘটনা ঘটেনি যার সঙ্গে তাঁর কোনও যোগ নেই

Premendra Mitra, the creator, described Ghanada in an interview by A K Ganguly published in SPAN in 1974, as below:

Ghana~da is a teller of tall tales, but the tales always have a scientific basis. I try to keep them as factually correct and as authentic as possible.