| Sir Henry Cowan | |
| Office: | Member of Parliament for Islington North |
| Term Start: | 6 December 1923 |
| Term End: | 10 May 1929 |
| Predecessor: | Sir Newton Moore |
| Successor: | Robert Young |
| Office2: | Member of Parliament for Aberdeen and Kincardine East |
| Term Start2: | 14 December 1918 |
| Term End2: | 26 October 1922 |
| Predecessor2: | Constituency created |
| Successor2: | Frederick Martin |
| Office3: | Member of Parliament for East Aberdeenshire |
| Term Start3: | 15 January 1910 |
| Term End3: | 25 November 1918 |
| Predecessor3: | Sir James Murray |
| Successor3: | Constituency abolished |
| Office4: | Member of Parliament for Guildford |
| Term Start4: | 12 January 1906 |
| Term End4: | 15 January 1910 |
| Predecessor4: | St John Broderick |
| Successor4: | Edgar Horne |
| Birth Date: | 1862 5, df=yes |
| Party: | Unionist Liberal |
Sir William Henry Cowan (22 May 1862 – 11 January 1932) was a politician in the United Kingdom.
The son of William Cowan and Elizabeth Giles, he was educated at Merchiston Castle School, Edinburgh Collegiate School and the University of Edinburgh.
He was elected as Liberal Member of Parliament (MP) for Guildford from 1906 to 1910 and for Aberdeenshire Eastern from 1910 to 1922, then as a Unionist for Islington North from 1923 to 1929. As a parliamentarian, Cowan became interested in matters concerning immigration including promoting immigration of British families to dominions such as Australia.
As of 1928, he was chairman of Parkinson and W. and B. Cowan, Limited, a manufacturer of gas meters and gas cookers.[1] [2]
He was knighted in the 1917 Birthday Honours.