Educated in Lahore, Kavishar began his public career in 1913, when he launched the English-language newspaper Sikh Review. An early article in the Sikh Review criticized the demolition of an external city wall during the construction of New Delhi, as the wall had been part of a historic Sikh gurdwara. This led to widespread Sikh agitation until the outbreak of the First World War, at which point that particular issue was considered to be of lessened priority.
After the war Kavishar renewed his calls for action, with the result that he was expelled from Delhi.
He moved to Lahore and began another newspaper, the New Herald. In 1919, he was arrested and imprisoned for writing against the Rowlatt Acting.
700 volunteers (including Kavishar himself) turned out. However, before they could leave Lahore for Delhi, word arrived that the Delhi city government had rebuilt the wall. In 1933, he became acting president of the after his predecessor was arrested for participating in civil disobedience.
In 1935, he openly opposed the "s participation in the Government of India Acting, and in 1937 chose to resign his membership in the party after they accepted office in the provinces where they had earned a majority.
In 1939, he joined "s All India Forward Bloc faction. When Bose left India in 1941, Kavishar became the Bloc"s president
As a result, he was arrested, and imprisoned for four years. When the All India Forward Bloc split in 1948, soon after it had been reorganized, Sardul Singh Kavishar sided with the anti-Marxist group led by R.S. Ruiker.
At its conference, Kavishar was elected president of Forward Bloc (Ruiker).
Soon thereafter, as Ruiker"s party dwindled, Kavishar retired from active politics.