Shri Jamir married Imkonglemla, daughter of Senkalemba in 1958 and they have been blessed with three sons and two daughters. His younger daughter died in 1996 leaving behind two sons. Shri and Smt. Jamir have ten grand children.
A Believer in all religion, up till today, he has rarely missed a Sunday Church Service when in the State. He had arranged for instance, land and donations for construction of Mandirs in Mokokchung and elsewhere. This secular and generous person in a public gathering had declared that he has forgiven those who assayed to kill him on four occasions and that he harbours no ill will towards the perpetrators.
In the 1950s Naga Hills were district in the undivided Assam and was experiencing a lot of violence and hardship. Under the guidance of the Naga People's Convention (NPC) in 1957, the Naga people met at Kohima to find a way to re-establish peace and normalcy in the land. In 1958, in the second meeting of the NPC held at Ungma village the Organizers made 27 years old man the Chairman of the Reception Committee, who was S.C Jamir.
He was unanimously elected as the Joint secretary of the NPC in the year 1959, when the third and final meeting of the NPC outlined a memorandum and submitted it to the Government of India. Some minor changes was mutually agreed upon by both the Government of India and after that the NPC which resulted in 1963, in the creation of Nagaland as the 16th State in the Indian Union. One of the signatories of this Agreement was Jamir and is today considered as one of the architects of modern Nagaland.
From the State of Nagaland, Shri Jamir was elected the first Lok Sabha Member. From 1961 to 1970, he has served as MP and during this period he has also served as the Union Deputy Minister of Railways, Labor & Rehabilitation, from 1968 to 1970, served as the Union Deputy Minister of Community Development & Cooperation, Food and Agriculture. He was attributed as the Parliamentary Secretary to Pandit Jawaharlal Nehru the then Prime Minister who also was in charge of External Affairs Ministry. In 1971, he was first voted to the Nagaland Legislative Assembly.
S.C Jamir is a person who since then has never lost any Assembly elections till date. Through various capacities he served the people of Nagaland. He was made the Chief Minister of Nagaland in 1980, 1982 to 1986, and 1993 to 2003. His tenure as the Chief Minister of Nagaland is considered as the longest. From 1993 to 2004, he was the President of the PCC, Nagaland for eleven years. He was a member of the Progressive United Democratic Front for his first two terms. By 1989 he had switched to the Indian National Congress.
When the Union Home Minister informed him in the first week of June that his name was incorporated in the list for Governorship, Jamir affirmed that he would be engrossed only if his name is short listed for what he called a "peaceful State like Goa". The media expressing his happiness and gratitude to the UPA Government at the Center has quoted him that his choice for Goa was considered. His Excellency Shri S. C. Jamir, Governor of Goa soon after assuming the charge, was given a Guard of Honour by the contingent of Goa Police, at Raj Bhavan.