John Logie Baird (1888–1946), television engineer, was born on 13 August 1888 at The Lodge, West Argyle Street, Helensburgh, Dunbartonshire, Scotland, the youngest of the four children of the Revd John Baird, minister of the West Parish Church, Helensburgh, and his wife, Jessie Morrison Inglis. Baird was educated at three schools in Helensburgh, between 1893 and 1906 when he was admitted to an electrical engineering course at the Glasgow and West of Scotland Technical College. In 1914 he was awarded an associateship of the college and then attended Glasgow University as a final year BSc degree student, but did not sit the examinations. In 1916, having obtained a position as an assistant mains engineer with the Clyde Valley Electrical Power Company, he applied for military service but was declared medically unfit. In 1918 he resigned from the Clyde Valley company to follow, full time, various entrepreneurial business ventures.

Baird had a flair for marketing, and from 1917 to 1922 sold—at different periods in Glasgow, the West Indies, and London—medicated socks, boot polish, solid scent, jam, honey, fertilizer, coir fibre, and soap. His initiatives were mostly successful, even though he was dogged by the ill health which was a feature of his life. In 1922 he retired to Hastings to recuperate from a severe illness and, while there, began to study the problems of transmitting and receiving visual signals, namely, television. His resources were meagre: he lacked formal research training, he did not have access to workshop or laboratory facilities, and his financial position was precarious. Nevertheless, he rented an attic and began to assemble apparatus using what were, on the face of it, most unpromising materials. His investigations attracted some very modest support, and by April 1925 Baird was able to demonstrate, in public, at Selfridge's Oxford Street store, in London, the transmission of crude outlines of simple objects. Later, on 2 October 1925, he succeeded in reproducing an image of an object, which had tone gradation. A formal demonstration was given to about forty members of the Royal Institution on 26 January 1926. This was the world's first demonstration of television (albeit at a very rudimentary stage), which had been sought by many inventors since 1878, when the possibility of ‘seeing at a distance’ was first proposed. It was an outstanding achievement. Subsequently his basic television scheme was adopted by inventors and companies in France, Germany, the USA, and elsewhere.

An examination of Baird's modus operandi in the 1920s shows that he endeavoured to emulate the policies which, from 1896, had ensured success for Marconi and his companies. Baird and his supporters followed a plan which embraced publicity and the demonstration of ‘firsts’, the accumulation of patents, and company formation. Television Ltd was registered on 11 June 1925, Baird Television Development Company Ltd was established in April 1927, and Baird International Television Ltd was launched on 25 June 1928. Baird tried to anticipate every conceivable application of television and to safeguard by patent protection its practical implementation. He eventually held 178 patents: of these, eighty-eight were granted by the end of 1930. From 1926 to 1931 Baird demonstrated, sometimes for the first time ever, low-definition noctovision (in which subjects were illuminated by infra-red rays), daylight television, colour television, stereoscopic television, phonovision (the recording of sound and image on a gramophone disc), large-screen television, and zone television. Unfortunately, the exaggerated and premature claims made by Baird's business partners reflected adversely on Baird himself. However, a critical appraisal of his early work, to 1931, shows that his thoughts on television, and the realization of those thoughts, were entirely consonant with the television concepts of the well endowed Bell Telephone Laboratories, whose demonstrations in the same period were unsurpassed anywhere. On 30 September 1929 the BBC transmitted, using the Baird 30-line system, its first experimental television broadcast. Later, on 22 August 1932, the first public (in the UK), 30-line television service was inaugurated by the BBC; it remained in operation until 15 September 1935.

In November 1931, in New York, Baird married Margaret Cecilia (d. 1996), a concert pianist, daughter of the late Henry Albu, diamond merchant, of Johannesburg. They had one son, Malcolm, and one daughter, Diana.

Baird's ‘blind spot’ was to ignore for too long the inevitable move towards high-definition television, using very high frequencies and all-electronic means. When the London television station was opened by the BBC on 2 November 1936, two systems of television were employed, on an alternate basis. The ensuing trial highlighted the advantages of the 405-line, all-electronic system recommended by Isaac Shoenberg of EMI compared to Baird Television's 240-line system, which was based on mechanical scanning. The former was chosen for the new station, and the last BBC transmission using the Baird system was sent out on 30 January 1937.

Undaunted, Baird continued his work, concentrating on large-screen, colour, and stereoscopic television. He had his own private laboratory (set up in 1933) and he operated entirely independently from Baird Television Ltd. In December 1936 he demonstrated 120-line theatre television using a 2.4 × 2 metre screen; and in February 1938 he displayed large-screen (3.65 metres × 2.75 metres) colour television pictures. Both demonstrations were at the Dominion Theatre, London. 600-line colour television and stereoscopic colour television systems were shown in December 1940 and December 1941 respectively. Baird was the first person, anywhere, to design, construct, and exhibit (in 1944) a multi-gun colour television tube (the telechrome tube).

Despite poor health, Baird continued his endeavours until he died, from coronary thrombosis, at his rented home, Instow, 1 Station Road, at Bexhill, Sussex, on 14 June 1946. He was buried in Helensburgh cemetery.