Kirton or Kirton in Holland is a historic market town and civil parish in the Borough of Boston, Lincolnshire, England. The population of the civil parish at the 2011 census was 5,371.

The Domesday Book of 1086 terms the village Cherchetune. It then had 52 households, with 30 freemen and 16 smallholders, 12 ploughlands, 10 plough teams, a meadow of 60 acres (24 ha), a church and two salt houses. In 1066 lordship of the manor was held by Earl Ralph. It had passed to Count Alan of Brittany by 1086.

Before the local-government changes of the late 20th century, the parish came under Boston Rural District in the Parts of Holland – one of three divisions or parts of the historic county of Lincolnshire, which the Local Government Act of 1888 made a county in itself in most respects.

The 1885 Kelly's Directory recorded a Kirton railway station on the Great Northern Railway line between Boston and Spalding line. The station closed in 1961.

There existed in the 19th century Congregational and Wesleyan chapels and almshouses for four poor women. The towns market was disused. A Gas Consumers' Company Ltd formed in 1865. The main landowners were the Mercers' Company, Sir Thomas Whichcote DL, E. R. C. Cust DL, the Very Rev. Arthur Percival Purey-Cust DD, and Samuel Smeeton, whose residence was the "modern white building" of D'Eyncourt Hall. The crops grown in the 8,962 acres (3,627 ha) parish were wheat, beans and potatoes. There was a "large quantity of pasture land" and 676 acres (274 ha) of marsh land. The 1881 the ecclesiastical parish population was 2,011, that of the civil parish, 2,580. Kirton in Holland Town Hall was opened in August 1912.

The parish church is dedicated to St Peter and St Paul. The transepts had double aisles like those of Algarkirk and Spalding, but, in 1804, the central tower and transepts were pulled down and the chancel shortened, the architect (Hayward) using gunpowder to remove the tower. This was completed by 1809. In 1900 a restoration of the rebuilt church was undertaken by the architect Hodgson Fowler.

In 1624, Thomas (later Sir Thomas) Middlecott was empowered by a private act of Parliament (21 Jas. 1. c. 8) to found a free grammar school for teaching the Latin and Greek languages and providing English commercial and agricultural education to children from the parishes of Kirton, Sutterton, Algarkirk and Fosdyke. By 1835, the school had 40 pupils, some attending free and some paying fees. The master (headmaster) appointed in 1773, Rev. Charles Wildbore (c. 1736–1802), and later his son by the same name (1767–1842), were later accused of diverting surplus income from the school's endowments for their own use and failing to keep up educational standards. This culminated in a parliamentary report, and ultimately a restructuring of the school management in 1851. By 1885, William Cochran was master and a new school house had been built next to his house. Under a scheme of the Endowed Schools Act 1869, amended in 1898, the school ranked as a "second-grade" grammar school.

In the 1830s the town gained a girls' school for 14 day and boarding pupils and a Sunday School for 32 boys and 16 girls.

The town now has a secondary modern school: Thomas Middlecott Academy.

The Old King's Head is a former public house listed as a Grade II historic building. The earlier part of it was built at the end of the 16th century. It underwent major alterations in 1661 in Artisan Mannerist Style. It is red brick in English bond, with recent tiles on a former thatched roof. It became a domestic residence in the 1960s, but had fallen into disrepair and was purchased in 2016 by Heritage Lincolnshire, which has assigned over £2 million for its restoration.

It opened as a cafe and bed & breakfast on 1 October 2021.

Kirton is on the main A16, B1397 and B1192 roads south of Boston, near Frampton and Sutterton. Several villages and hamlets take their name from Kirton, including Kirton Holme, Kirton End, Kirton Fen, Kirton Skeldyke, and Kirton Marsh. Until 1961/64, the town had a railway station on the Lincolnshire Loop Line from Boston to Spalding. It is now part of the A16 road which runs through the old station site and on the trackbed.

The parish contained the ancient manor of Kirton Meres, the seat of Roger de Kirton (d. 1383), alias de Kirketon / Roger de Meres / Meeres), a Justice of the Common Pleas (1371–1380). The manor house (later known as "Orme Hall") was demolished in 1818 but the arched gatehouse (Porter's Lodge, built of brick, guard room, and chambers over it, with stone dressings, windows, archway, door-ways, and copings, surmounted by highly pitched step gables, with 15 sculpted heraldic shields, some now held by the Spalding Gentlemen's Society, Broad Street, Spalding, Lincs) survived until 1925 on the south side of the Willington Road, one mile west of the town of Kirton. Another of this family resident at Kirton Meres was the churchman Francis Meres (1565–1647).

Local governance of the town was reorganised on 1 April 1974, as a result of the Local Government Act 1972. Kirton parish forms its own electoral ward.

Kirton falls within the drainage area of the Black Sluice Internal Drainage Board.

The former Kirton Research Centre was nearby. Ownership of the 120-acre (0.49 km) centre for horticultural research was transferred from the Department for Environment, Food and Rural Affairs to the University of Warwick in April 2004 and it became part of Horticulture Research International. In August 2009 the University closed it, as public and private funding fell £2 million short of covering its annual running costs.

In order of birth:

• Francis Meres (1565/1566 – 1647), churchman and author
• Joseph Gilbert (1732–1821), born in Kirton, was Master of HMS Resolution on Cook's second voyage.
• Dame Sarah Swift (1854–1937), born in Kirton Skeldyke, set up the Royal College of Nursing.
• Harold Jackson VC (31 May 1892 – 24 August 1918), a sergeant in The East Yorkshire Regiment who received the Victoria Cross in 1917 and was killed a year later, came from Allandale, Kirton.
• Oliver "Ollie" Ryan (born 1985), footballer, attended Kirton Primary School.

• Attorney General v Davy (1741) 26 ER 531, a leading legal case in UK company law

• Parish council
• Kirton News
• Kirton Brass Band
• Sea Scouts
• Kirton Primary School
• Middlecott School
• Kirton Town Hall.

• Horticultural research station to close in 2009