Born in Leicester to Ada and William Snow (a church organist and choirmaster), Charles was the second of four boys (his brothers being Harold, Eric and Philip Snow). Snow was educated at the Leicestershire and Rutland College, now the University of Leicester, and the University of Cambridge, where he became a Fellow of Christ's College in 1930.

He served in several senior positions in the government of the United Kingdom: as technical director of the Ministry of Labour from 1940 to 1944; as civil service commissioner from 1945 to 1960; and as parliamentary secretary to the Minister of Technology from 1964 to 1966. He was knighted in 1957 and made a life peer, as Baron Snow of the City of Leicester, in 1964.

Snow married the novelist Pamela Hansford Johnson in 1950. They had one son. Friends included the mathematician G. H. Hardy, for whom he would write a brief biographical foreword in A Mathematician's Apology, the physicist P.M.S. Blackett, the X-ray crystallographer J.D. Bernal and the cultural historian Jacques Barzun. In 1960, he gave the Godkin Lectures at Harvard University, about the clashes between Henry Tizard and F. Lindemann (later Lord Cherwell), both scientific advisors to British governments around the time of World War II. The lectures were subsequently published as Science and Government. For the academic year 1961 to 1962, Lord and Lady Snow served as Fellows on the faculty in the Center for Advanced Studies at Wesleyan University.

Snow's first novel was a whodunit, Death under Sail (1932). In 1975 he wrote a biography of Anthony Trollope. But he is better known as the author of a sequence of novels entitled Strangers and Brothers depicting intellectuals in academic and government settings in the modern era. The Masters is the best-known novel of the sequence. It deals with the internal politics of a Cambridge college as it prepares to elect a new master, and has all the appeal of being an insider’s view. The novel depicts concerns other than the strictly academic influencing the decisions of supposedly objective scholars. The Masters and The New Men were jointly awarded the James Tait Black Memorial Prize in 1954. Corridors of Power added a phrase to the language of the day.In 1974, Snow's novel In Their Wisdom was shortlisted for the Booker Prize.

In The Realists, an examination of the work of eight novelists ... Stendhal, Honoré de Balzac, Charles Dickens, Fyodor Dostoevsky, Leo Tolstoy, Benito Pérez Galdós, Henry James and Marcel Proust ... Snow makes a robust defence of the realistic novel.

The storyline of his novel, The Search, is referenced in Dorothy L. Sayers' Gaudy Night, and is used to help elicit the murderer's motive.

On 7 May 1959, Snow delivered an influential Rede Lecture called The Two Cultures, which provoked "widespread and heated debate". Subsequently published as The Two Cultures and the Scientific Revolution, the lecture argued that the breakdown of communication between the "two cultures" of modern society ... the sciences and the humanities ... was a major hindrance to solving the world's problems. In particular, Snow argues that the quality of education in the world is on the decline. For example, many scientists have never read Charles Dickens, but artistic intellectuals are equally non-conversant with science. He wrote:

A good many times I have been present at gatherings of people who, by the standards of the traditional culture, are thought highly educated and who have with considerable gusto been expressing their incredulity at the illiteracy of scientists. Once or twice I have been provoked and have asked the company how many of them could describe the Second Law of Thermodynamics. The response was cold: it was also negative. Yet I was asking something which is about the scientific equivalent of: 'Have you read a work of Shakespeare's?'

I now believe that if I had asked an even simpler question ... such as, What do you mean by mass, or acceleration, which is the scientific equivalent of saying, 'Can you read?' ... not more than one in ten of the highly educated would have felt that I was speaking the same language. So the great edifice of modern physics goes up, and the majority of the cleverest people in the western world have about as much insight into it as their Neolithic ancestors would have had.

The satirists Flanders and Swann utilised the first part of this quotation as the basis for their short monologue and song "First and Second Law".

As delivered in 1959, Snow's Rede Lectures specifically condemned the British educational system, as having since the Victorian period over-rewarded the humanities (especially Latin and Greek) at the expense of scientific education. This in practice deprived British elites (in politics, administration, and industry) of adequate preparation to manage the modern scientific world. By contrast, Snow said, German and American schools sought to prepare their citizens equally in the sciences and humanities, and better scientific teaching enabled these countries' rulers to compete more effectively in a scientific age. Later discussion of The Two Cultures tended to obscure Snow's initial focus on differences between British systems (of both schooling and social class) and those of competing countries.

Fiction

Strangers and Brothers Series

• George Passant (first published as Strangers and Brothers), 1940
• The Light and the Dark, 1947
• Time of Hope, 1949
• The Masters, 1951
• The New Men, 1954
• Homecomings, 1956
• The Conscience of the Rich, 1958
• The Affair, 1959
• Corridors of Power, 1963
• The Sleep of Reason, 1968
• Last Things, 1970

Other Fiction

• Death Under Sail, 1932
• New Lives for Old, 1933
• The Search, 1934
• The Malcontents, 1972
• In Their Wisdom, 1974, shortlisted for the Booker Prize
• A Coat of Varnish, 1979

Non-fiction

• Science and Government, 1961
• The two cultures and a second look, 1963
• Variety of men, 1967
• The State of Siege, 1968
• Public Affairs, 1971
• Trollope: His Life and Art, 1975
• The Realists, 1978
• The Physicists, 1981