| # | Tower | No | Year | Materials | Maker | Trusses | Layout |
|---|
| 4551 | Isle of Sark, Sark, Channel Islands, S Peter | 1 | c1883 | Softwood | | 6 | |
| 4552 | Isleham, Cambridgeshire, S Andrew | 9 | | | | | |
| 4553 | Isleham, Cambridgeshire, S Andrew | 1 | 1969 | Cast iron | John Taylor & Co | 8.3.A.h | 6.1 |
| 4554 | Isleworth, Greater London, All Saints | 8 | | | | | |
| 4555 | Isleworth, Greater London, All Saints | 2 | 1931 | Metal | Mears & Stainbank | | |
| 4556 | Isleworth, Greater London, All Saints | 1 | 1903 | Cast iron | John Taylor & Co | 8.3.C.e | |
| 4557 | Islington, Greater London, S Mary V | 1 | 2002 | Cast iron | Hayward Mills Associates | 8.3.A.h | 8.3 D |
| 4558 | Islip, Northamptonshire, S Nicholas | 1 | 1892 | Cast iron & oak | John Taylor & Co | | 6 |
| 4559 | Itchen Stoke, Hampshire, S Mary V | 1 | | Stone | | 9.A | 1 |
| 4560 | Itchingfield, West Sussex, S Nicolas | 1 | 1866 | Timber | | 6.A | 5.1 |
| 4561 | Iver, Buckinghamshire, S Peter | 1 | 1938 | Steel | Gillett & Johnston | 8.1.B.d | 8.3 |
| 4562 | Ivinghoe, Buckinghamshire, S Mary V | 1 | c1715 | Timber | | 6.A & 6.H | |
| 4563 | Ivychurch, Kent, S George | 1 | c1599 | Timber | | | |
| 4564 | Iwerne Courtney, Dorset, S Mary | 1 | 1908 | Wrought steel | Mears & Stainbank | 8.1.B.a | 6.5 R |
| 4565 | Iwerne Minster, Dorset, S Mary | 2 | 1979 | Steel | Whitechapel Bell Foundry | | |
| 4566 | Iwerne Minster, Dorset, S Mary | 1 | 1979 | Cast iron & steel | Whitechapel Bell Foundry | 8.3.A | 5.1 |
| 4567 | Ixworth, Suffolk, S Mary | 1 | 1882 | Timber | George Bullock | 6.A & ~ 6.F | 8.X |
| 4568 | Jacobstow, Cornwall, S James | 1 | 1970 | Iroko | Whites of Appleton | | |
| 4569 | Jacobstowe, Devon, S James | 1 | 1904 | Cast iron | John Taylor & Co | 8.3.C.e | 5.4 |
| 4570 | Jarrow, Tyne and Wear, S Mark | 1 | | Stone | | 9.A | 2.X1 |
| 4571 | Jesmond, Tyne and Wear, S George | 2 | 1888 | Composite | John Taylor & Co | 7.A.a | 2.X1 |
| 4572 | Jesmond, Tyne and Wear, S George | 1 | 1888 | Cast iron | John Taylor & Co | 8.3.C.b | 6.4 |
| 4573 | Johannesburg, Gauteng, South Africa, All Saints, Fourways Gardens | 1 | 2005 | Steel | Locally manufactured | 8.1.B.c | 6.1 |
| 4574 | Johannesburg, Gauteng, South Africa, S George, Parktown | 1 | 1980 | Steel | Local labour/guild/assn | 8.1.B.c | 8.3 |
| 4575 | Johannesburg, Gauteng, South Africa, S Peter's School, Paulshof | 1 | 2011 | Steel | Matthew Higby & Co | 8.1.B.a | 6.4 |
| 4576 | Kalamazoo, Michigan, United States of America, Stetson Chapel, Kalamazoo College | 1 | 1983 | Steel | Whitechapel Bell Foundry | 8.1.B.c | 8.3 |
| 4577 | Katoomba, New South Wales, Australia, S Hilda | 2 | 2016 | Steel | Local labour/guild/assn | | |
| 4578 | Katoomba, New South Wales, Australia, S Hilda | 1 | 2016 | Steel | Local labour/guild/assn | | |
| 4579 | Keddington, Lincolnshire, S Margaret | 1 | | Brick | | 9.A | 1 |
| 4580 | Kedington, Suffolk, S Peter & S Paul | 1 | 1935 | Oak | Whites of Appleton | 6.A | 6.1 |
| 4581 | Keelby, Lincolnshire, S Bartholomew | 1 | | Timber | | 6.A, 6.B & 6.I | 3.3 |
| 4582 | Keele, Staffordshire, S John | 2 | 1870 | Oak | Mears & Stainbank | 6.S | 1 |
| 4583 | Keele, Staffordshire, S John | 1 | 1870 | Oak | Mears & Stainbank | 6.S | 5.1 |
| 4584 | Keele, Staffordshire, Woodlands | 1 | 1992 | Steel | Phil Gay | 8.1.B | 8.X |
| 4585 | Keevil, Wiltshire, S Leonard | 1 | 1903 | Metal | Llewellins & James | 8.3.A.h | 6.4 |
| 4586 | Kegworth, Leicestershire, S Andrew | 2 | 1940 | Steel | John Taylor & Co | 8.1.B | 2.X2 |
| 4587 | Kegworth, Leicestershire, S Andrew | 1 | 1903 | Cast iron | John Taylor & Co | 8.3.C.e | 6.5 R |
| 4588 | Keighley, West Yorkshire, S Andrew | 1 | 1914 | Cast iron | Gillett & Johnston | | 8.3 |
| 4589 | Keinton Mandeville, Somerset, S Mary Magd | 1 | | Oak | | | 3.1 |
| 4590 | Kelham, Nottinghamshire, S Wilfrid | 1 | 1891 | Oak | Robert Lee | 6.B | 4.X ➔ 6.4 |
| 4591 | Kelham, Nottinghamshire, S Wilfrid | 1.1 | 2019 | Oak | TLB Services | 6.B | 2.X2 |
| 4592 | Kelly, Devon, S Mary V | 1 | 1867 | Oak | Thomas I Hooper | 6.D | 6.13 |
| 4593 | Kelmarsh, Northamptonshire, S Denys | 1 | 1886 | Cast iron | John Taylor & Co | 8.3.C.b | 6.4 |
| 4594 | Kelsale, Suffolk, S Peter | 2 | 1831 | Oak | | 6.A | 2.X2 |
| 4595 | Kelsale, Suffolk, S Peter | 1 | c1750 | Oak | | 6.A | 6.X |
| 4596 | Kelshall, Hertfordshire, S Faith | 1 | 1642 | Timber | | | 5.1 |
| 4597 | Kelston, Somerset, S Nicholas | 1 | 1931 | Cast iron | John Taylor & Co | 8.3.A.h | 6.1 |
| 4598 | Kelvedon, Essex, S Mary V | 2 | 2006 | Cast iron | John Taylor & Co | 8.3.D.a | 3.3 |
| 4599 | Kelvedon, Essex, S Mary V | 1 | 2006 | Cast iron | John Taylor & Co | 8.3.D.a | 5.3 |
| 4600 | Kemberton, Shropshire, S Andrew | 9 | | Timber | Local labour/guild/assn | 6.A | 6.4 |