|Centuries:||18th century - 19th century - 20th century|
|Decades:||1810s 1820s 1830s - 1840s - 1850s 1860s 1870s|
|Years:||1840 1841 1842 1843 1844 1845 1846 1847 1848 1849|
- February 15 - In today's issue of the Times and Seasons, Joseph Smith was named editor and publisher.
- March 1 - Articles of Faith first published in the Times and Seasons. They began as a portion of the Wentworth letter.
- March 17 - Joseph Smith organizes the Women's Relief Society.
- May 4 - First endowments given to seven men at a meeting in the room over Joseph Smith's store in Nauvoo.
- September 1 - At Nauvoo,Illinois, Joseph Smith writes letter to the Saints which becomes D&C 127.
- September 6 - At Nauvoo,Illinois, Joseph Smith writes letter to the Saints which becomes D&C 128.