In 1912, Bhagat joined the District Primary School in Lyallpur and recieved his elementary education there till class IV. In 1916 his family shifted to Lahore so he had to leave the Primary School. In Lahore, he was admitted to the Dayanand Anglo-Vedic (D.A.V) School, and he received rest of his primary education from there. When he was in 8th standard, the Jallianwala Bagh massacre took place. The very next day (on 14th April) he went to the bagh telling at his home that he was going to school. After running about 12 miles from Lahore, Bhagat reached Amritsar. On 2 pm as the boy Bhagat entered the bagh's compound he saw blood scattered all over the ground. The turbans and torn clothes of people laid lifeless on the ground. The walls of the compound were red with blood. As it was curfew in Punjab those days, the blood hadn't been cleaned. Bhagat had taken a glass bottle with him before leaving from home. He took a handful of blood-stained soil and put it in the bottle. He reached home and put the bottle on infront of the Sikh gurus potrait and prayed to him for peace and solace for the victims of the massacre and he pledged to teach the British a lesson.
In 1920, Mahatma Gandhi launched the Non-cooperation movement to encourage a mass protest against the British and to boycott their trade in India and to end their cooperation with the British rule. Many people joined the movement and discarded the use of foreign goods and clothes. The people boycotted schools and colleges. The factories, industries, shops & hospitals run by government were all boycotted. Many students also left British schools and joined Indian schools.
Bhagat Singh also actively participated in the movement. He along with a group of people used to burn foreign clothes publicly and used to boycott foreign schools, he was only 13 years old.
In February 1922, In Chauri Chaura village of Gorakhpur in United Provinces, Non violent actvists of the town lead a march to a nearby liquor shop to picket it. Some policemen beated down activists. The protesters became angry and they burnt down the police station where the policemen were hidden killing all 22 policemen inside. Mahatma Gandhi was shocked to hear about the incident and he halted the non- cooperation movement realizing that the people had still not understood the message of non-violent protest against the British. This created much chaos around the common people as they thought that if Gandhi had not suspended the movement they would have easily gained freedom.
Bhagat also came to know of this. He also was equally shocked about halting of the movement. He ran away from he to go to Chauri Chaura but his father soon came to know of it and stopped him at Bathinda.
In 1923, He joined the National College in Lahore. There he studied as well took part in many extracurricular activities. In August 1923, an essay competition was held at the college by Punjab Hindi Sahitya Sammelan. The topic was to write about any of the special acknowledgements about Punjab. Bhagat Singh wrote an essay on the following topic:
Besides this, a month later he joined a Dramatics Society near the college campus and began to organize functions and shows.
In late October, he had organized a show for the governor of Punjab. When the governor Edward Douglas Maclagan arrived the theatre. The Indian people present there did not do anything in respect of the governor. They treated him very casually. He became so angry with the irrespective treating that he walked out of the theatre, but Bhagat Singh didn't mind and performed the show infront of the citizens of his motherland.
While studying in National College, he used to spend most of his time in the College Library reading books about armed revolution in foreign countries.
He was inspired by the Russian revolutionaries who believed that armed revolt can only bring freedom. His first act which brought to notice was that occured in March 1924. It is said that one of his friend's bullock cart driver was beaten harshly by some English officials as the sign the outside the office of the officials read - 'Indians are not allowed'. He took revenge and along with Sukhdev he attacked the officials car and beated them with clubs and sticks and escaped unnoticed in the night.
In April, his father asked him to get married for which he refused. His father pressurised him for it, so one night, he quietly left his home for going to Kanpur. Before leaving he wrote a letter to his father:
Bhagat Singh worked for Ganesh Shankar Vidyarthi in the newspaper Pratap Press in Kanpur for some months. Then he met Chandra Shekhar Azad and they began to work together for freedom struggle.
In early 1925, his father called him home as his mother was very ill. He wrote to him for coming home, promising he would not force him to get married:
In March 1925, he accepted his father's wish returned to Lyallpur but had to soon escape from there as police had came to know of his whereabouts. He went to Delhi and started publishing the Daily Veer Arjun Newspaper for 6 months.
In October, he returned to Kanpur to free the Kakori prisoners who had been arrested after the train robbery in Kakori (9 August) along with their leader Ram Prasad Bismil. The prisoners were temporarily kept in Kanpur Station Cell before being shifted to different Central Jails.
On 22 November, along with Azad, Bhagat went to to the Station Cell unnoticed and broke the lockups and freed one their comrade but the police soon arrived there and they had to run away. Thus the plan failed.
In March 1926, he organized the Naujawan Bharat Sabha to encourage the young men of his country to fight for there freedom. He began to address big public meetings and asked them to overthrow the British rule from India. He also took the help of Dramatics Society for the purpose of spreading his message.
On 16 March 1927, Singh ordered a felt hat from an Italian Textile factory Giusippe Cambiaghi. The hat costed him ₹ 57. The highest price of a hat at that time.
On 16 October, when the Dussehra festival fair was held in Lahore Maidan. At 7:10 pm a bomb exploded in crowded section of Maidan when the Ramleela procession was being taken out. About 10 people died in this explosion and about five times of that were injured. People rushed out of the Maidan to save their lives.
Next day, "The Tribune" was published as follows-
The British Government took advantage of the incident and arrested Bhagat on the pretext that he was involved in the bomb incident on 29 May 1927. The real reason for his arrest was to stop him from addressing people to unite against the British rule.
It was later found that the bomb explosion was caused by a man named Channa Adin who was bribed by the Lahore police for committing such an act to get an opportunity for blaming the revolutionaries.
He was released on a security of ₹ 60,000 (about ₹ 25,00,000 of today) for having found no evidence against him, about a month later.
He became involved in numerous revolutionary activities. He quickly gained prominence in the Hindustan Republican Association (HRA) and became one of its chief leaders. Eventually, the name of the organization was changed to Hindustan Socialist Republican Association (HSRA) on 9 September 1928.
A Commission known as Simon Commission was appointed by the British Government to look after the administration of India for further political reforms. The commission which reached India on 3 February 1928 decided to tour the whole India to gain the first hand information of the condition of the administration. But there were no Indians in the commission, this angered many Indian political leaders who lead protests against the commission.
The leaders lead marches and rallies wherever the commission went using the slogan 'Simon Go Back'.