| 44251 | April 17 | Event | 1969 – Communist Party of Czechoslovakia chairman Alexander Dubček is deposed. |
| 44252 | April 17 | Event | 1970 – Apollo program: The ill-fated Apollo 13 spacecraft returns to Earth safely. |
| 44253 | April 17 | Event | 1971 – The People's Republic of Bangladesh forms, under Sheikh Mujibur Rahman at Mujibnagor. |
| 44254 | April 17 | Event | 1973 – George Lucas begins writing the treatment for The Star Wars. |
| 44255 | April 17 | Event | 1975 – The Cambodian Civil War ends. The Khmer Rouge captures the capital Phnom Penh and Cambodian government forces surrender. |
| 44256 | April 17 | Event | 1978 – Mir Akbar Khyber is assassinated, provoking a communist coup d'état in Afghanistan. |
| 44257 | April 17 | Event | 1982 – Patriation of the Canadian constitution in Ottawa by Proclamation of Elizabeth II, Queen of Canada. |
| 44258 | April 17 | Event | 1984 – Police Constable Yvonne Fletcher is killed by gunfire from the Libyan People's Bureau (Embassy) in London during a small demonstration outside the embassy. Ten others are wounded. The events lead to an 11-day siege of the building. |
| 44259 | April 17 | Event | 1986 – The Three Hundred and Thirty Five Years' War between the Netherlands and the Isles of Scilly ends. |
| 44260 | April 17 | Event | 1986 – Nezar Hindawi's attempt to detonate a bomb aboard an El Al flight from London to Tel Aviv is thwarted. |
| 44261 | April 17 | Event | 2006 – A Palestinian suicide bomber detonates an explosive device in Tel Aviv, killing 11 people and injuring 70. |
| 44262 | April 17 | Event | 2013 – An explosion at a fertilizer plant in the city of West, Texas, kills 15 people and injures 160 others. |
| 44263 | April 17 | Event | 2014 – NASA's Kepler confirms the discovery of the first Earth-size planet in the habitable zone of another star. |
| 44264 | April 17 | Birth | 1277 – Michael IX Palaiologos, Byzantine emperor (d. 1320) |
| 44265 | April 17 | Birth | 1573 – Maximilian I, Elector of Bavaria (d. 1651) |
| 44266 | April 17 | Birth | 1586 – John Ford, English poet and playwright (d. 1639) |
| 44267 | April 17 | Birth | 1598 – Giovanni Battista Riccioli, Italian priest and astronomer (d. 1671) |
| 44268 | April 17 | Birth | 1620 – Marguerite Bourgeoys, French-Canadian nun and saint, founded the Congregation of Notre Dame of Montreal (d. 1700) |
| 44269 | April 17 | Birth | 1622 – Henry Vaughan, Welsh physician, author, and poet (d. 1695) |
| 44270 | April 17 | Birth | 1676 – Frederick I of Sweden (d. 1751) |
| 44271 | April 17 | Birth | 1683 – Johann David Heinichen, German composer and theorist (d. 1729) |
| 44272 | April 17 | Birth | 1710 – Henry Erskine, 10th Earl of Buchan, Scottish politician (d. 1767) |
| 44273 | April 17 | Birth | 1734 – Taksin, Thai king (d. 1782) |
| 44274 | April 17 | Birth | 1741 – Samuel Chase, American lawyer and jurist (d. 1811) |
| 44275 | April 17 | Birth | 1750 – François de Neufchâteau, French academic and politician, French Minister of the Interior (d. 1828) |
| 44276 | April 17 | Birth | 1756 – Dheeran Chinnamalai, Indian commander (d. 1805) |
| 44277 | April 17 | Birth | 1766 – Collin McKinney, American surveyor, merchant, and politician (d. 1861) |
| 44278 | April 17 | Birth | 1794 – Carl Friedrich Philipp von Martius, German botanist and explorer (d. 1868) |
| 44279 | April 17 | Birth | 1798 – Étienne Bobillier, French mathematician and academic (d. 1840) |
| 44280 | April 17 | Birth | 1814 – Josif Pančić, Serbian botanist and academic (d. 1888) |