Ramdhari Singh (23 September 1908 – 24 April 1974), known by his pen name Dinkar, was an Indian Hindi language poet, essayist, freedom fighter, patriot and academic. He emerged as a poet of rebellion as a consequence of his nationalist poetry written in the days before Indian independence. His poetry exuded Veer Rasa (heroic sentiment), and he has been hailed as a Rashtrakavi ('national poet') and Yuga-Chāraṇa (Charan of the Era) on account of his inspiring patriotic compositions. He was a regular poet of Hindi Kavi Sammelan and is hailed to be as popular and connected to poetry lovers for Hindi speakers as Pushkin for Russians.

One of the notable modern Hindi poets, Dinkar was born in Simaria village of Bengal Presidency, British India, now part of Begusarai district in Bihar state. The government honored him with the Padma Bhushan in 1959 and nominated him three times to the Rajya Sabha. Similarly, his political thought was greatly shaped by both Mahatma Gandhi and Karl Marx. Dinkar gained popularity in the pre-independence period through his nationalist poetry.

Dinkar initially supported the revolutionary movement during the Indian independence struggle, but later became a Gandhian. However, he used to call himself a "Bad Gandhian" because he supported the feelings of indignation and revenge among the youth. In Kurukshetra, he accepted that war is destructive but argued that it is necessary for the protection of freedom. He was close to prominent nationalists of the time such as Rajendra Prasad, Anugrah Narayan Sinha, Sri Krishna Sinha, Rambriksh Benipuri and Braj Kishore Prasad.

Dinkar was elected three times to the Rajya Sabha, and he was the member of this house from 3 April 1952 to 2 April 1964, and was awarded the Padma Bhushan in 1959. He was also the Vice-Chancellor of Bhagalpur University (Bhagalpur, Bihar) in the early 1960s.

During The Emergency, Jayaprakash Narayan had attracted a gathering of one lakh (100,000) people at the Ramlila grounds and recited Dinkar's famous poem: Singhasan Khaali Karo Ke Janata Aati Hai ('Vacate the throne, for the people are coming').

Dinkar was born on 23 September 1908, in Simaria village, Bengal Presidency, British India, (now in Begusarai district in Bihar) in a Bhumihar family to Babu Ravi Singh and Manroop Devi. He was married in Tabhka village of Samastipur district in Bihar. As a student, his favourite subjects were history, politics and philosophy. At school and later in college, he studied Hindi, Sanskrit, Maithili, Bengali, Urdu and English literature. Dinkar was greatly influenced by Rabindranath Tagore, Keats and Milton and translated works of Rabindranath Tagore from Bengali to Hindi. The poetic persona of the poet Dinkar was shaped by the pressures and counter-pressures of life during the Indian freedom movement. A tall man at 5 ft 11 in (1.80 m), with a fair complexion, prominent nose, large ears and broad forehead, he had a distinctive appearance. He worked as a Hindi teacher at Langat Singh College, Muzaffarpur, Bihar from 1950-1952.

As a student, Dinkar had to battle day to day issues, some related to their family's economic circumstances. When he was a student of Mokama High School, it was not possible for him to stay on until school closed at four p.m. as he had to leave the class after the lunch break to catch the steamer back home. He could not afford to be in the hostel which would have enabled him to attend all periods. How could a student who had no shoes on his feet manage the hostel fees? His poetry later showed the impact of poverty. This was the environment in which Dinkar grew up and became a nationalist poet of radical views. In 1920, Dinkar saw Mahatma Gandhi for the first time. About this time, he founded Manoranjan Library at Simariya. He also edited a handwritten pamphlet.

When Dinkar stepped into his adolescence, the Indian freedom movement had already begun under the leadership of Mahatma Gandhi. In 1929, when after matriculation, he entered Patna College to study intermediate; this movement started becoming aggressive. In 1928, the Simon Commission, against which nationwide demonstrations were being held, arrived. Demonstrations were held in Patna too led by Maghfoor Ahmad Ajazi and Dinkar too signed the oath-paper. Thousands came to the rally at Gandhi Maidan in which Dinkar also participated. During the protest against Simon Commission, the police of the British government mercilessly lathi charged the Lion of Punjab, Lala Lajpat Rai, who succumbed to the injuries. The whole country was in turmoil. The youthful mind of Dinkar became increasingly radical due to these agitations. His emotional nature was charged with poetic energy.