* Lincoln Castle was ordered to be built by William I as he returned south after dealing with a rebellion in the north. 166 houses were demolished in order to make way for it
* A great earthquake killed many cattle in Lincolnshire (14 November)
* One of the Witches of Belvoir, Margaret Flower was hanged at Lincoln (11 March). Her mother Joan, also accused of witchcraft, had died before the trial and her sister Philippa, another convicted witch, escaped execution by drugging the prison guards.
* An endowed school was founded at Raithby by Spilsby
* Dr Francis Willis, who treated George III's madness, was born in Lincoln on 17 August. He was a physician and clergyman who developed as a private rural sanatorium for mentally ill patients at Greatford near Bourne.
* Laurence Eusden appointed Poet Laureate (24 December). At the age of 30 he was the youngest poet to hold the post and, in the view of some, the most obscure. He became Rector of Coningsby in the 1720s and died there in 1730.
* Birth of William Marwood, cobbler in Horncastle, who became hangman for the British government and developed the relatively humane technique of hanging known as the "long drop".
* Execution in Lincoln of Richard Randall and John Tubbs, both of Lutton, for highway robbery; also, on the same day, Thomas Norris of Rauceby and Thomas Evison of West Ashby for setting fire to a threshing machine at Anwick; the "new drop" method was deployed. (27 March)
* Thomas Bernard, born Lincoln, died on 1 July. He became 3rd Baronet (succeeding to his father's baronetcy) and was a notable English social reformer, lawyer and author. He was active in promoting vaccination and was also a Director and leading proponent of the Regent's Canal in London.
* James Elphinstone Roe (1818-1897), born Kirkby on Bain. Following conviction for forgery and transportation to Australia in 1862, he became an influential education reformer and journalist in the new colony.
* The death occurred on 11 August of Robert Carr Brackenbury, who had been born at Panton Hall. He was a friend of John Wesley and an active Methodist, building both Raithby Chapel (1779) and Raithby Hall.
* Thomas Parry, partner of Charles Kirk, architect, born Sleaford (23 Feb). He also served as Liberal MP for Boston for three short periods in the 1860s and 70s.* Boston's Town Bridge opened (18 July)
* Priscilla Biggadyke, who had poisoned her husband, was executed at Lincoln Prison, the first woman to be executed inside a prison (28 December).
* A crowd of 50,000 spectators watched the launch of the new 12-oared lifeboat Manchester Unity at Cleethorpes (17 August).
* The Ancholme Rowing Club founded in Brigg
* The branch railway line to Spilsby from Firsby on the East Lincolnshire Line opened on 1 May.
* King George V and Queen Mary travelled by train to visit Lincoln (9 April), Immingham and Grimsby (10 April) and Cranwell (11 April).
In Lincoln they spent time at Ruston Proctors, Fosters (where the King rode in a tank), Clayton & Shuttleworth, Robeys, the Cathedral and the Fourth Northern General Hospital.
At Immingham the King met naval officers and held an Investiture for more than 50 men. Later in the day the royal party visited trawlers in Grimsby and were shown the curing and packing of fish.
Cranwell was the focus of the final day in the county; here they met officers of the newly created RAF, learned about dropping bombs, visited the lighter-than-air section of the aerodrome and saw the quarters of their son Prince Albert (later George VI).
* Formation of the agricultural and industrial engineering company Ruston and Hornsby Ltd by the amalgamation of Ruston, Proctor and Company of Lincoln and Richard Hornsby and Sons of Grantham (11 September)
* Seven corn stacks destroyed and a threshing machine damaged by fire at Pinchbeck Marsh, one of a number of protests against employers refusing jobs to discharged soldiers (5 September)
* The Vicar at Kirton Lindsey was unable to take the Sunday services because of Spanish influenza (14 July). In the month of November 113 deaths, mainly from "Spanish flu", were recorded in Grimsby.
* The well-travelled tank Egbert was stationed in the People's Park to help raise funds during Tank Week in Grimsby (July)
* The Royal Air Force was created by the amalgamation of the Royal Flying Corps and the Royal Naval Air Service (1 April). RAF Cranwell, taken over from the Royal Navy, began officer cadet training in the same year (the RAF College opened two years later).
* The completion of Ruston, Proctor's thousandth aeroplane in their Lincoln factory (4 Jan)
* Eamon de Valera, Irish political leader, arrested in May and imprisoned at Lincoln.
* Guy Gibson was born (12 August). He was Commanding Officer of RAF No.617 ("Dambuster") Squadron based at Scampton in 1943.
* Harold Jackson of Boston was awarded the Victoria Cross for an act of bravery at Hermies, France on 22 March
* Louth Open Air School was opened on 15 July 1918 in new buildings at the rear of the Technical School, as part of the Open Air School movement, and was the first such school in Lincolnshire.
* Kesteven and Sleaford Girls' High School taken over by Kesteven County Council in 1918.
* Watson's Infants' School, Horncastle closed. This small school on West Street was originally endowed by Richard Watson, son of a prosperous Horncastle tanner, in 1786.
* A number of Lincolnshire schools opened in new buildings: City School, Lincoln (in Skellingthorpe Road, replacing the old school in Monks Road), North Hykeham All Saints CE Primary School (in Ravensmoor Close), Anwick CE Primary School, and Deeping St James County Primary School
* Primary schools closed in the following villages: Beckingham, East Keal, Frampton, Kirton Holme, Southrey, South Somercotes and Swallow* Freddie Frinton, comedian, music hall artiste and television actor, died (16 October). He was born in Grimsby in 1909.