2017 County Championship
The 2017 County Championship, was the 118th cricket County Championship season. It was announced in March 2016 that the season would feature eight teams in Division One and ten teams in Division Two, meaning that at the end of the 2016 season only one team was promoted from Division Two whilst two were relegated from Division One. The first round of fixtures began on 7 April, with the final matches completed on 28 September. All of the fixtures starting on 26 June 2017 were played as day/night matches.
Following a series of financial "bailout" payments made by the England and Wales Cricket Board to Durham during the 2016 season, the county, which had finished fourth in Division One at the end of the season, were relegated to Division Two in place of the eighth place team, Hampshire. Durham were also placed under a salary cap administered by the ECB until 2020 and started the 2017 Championship season with a deduction of 48 points. Ahead of the season, each team played a first-class match against a MCC University team.
Teams
The 2017 Championship was divided into two divisions, Division One with eight teams, Division Two with 10 teams.Teams in both divisions played a total of 14 games, with all Division One teams playing each other twice, while Division Two teams played five counties twice and four once.
Division One
Team promoted from Division Two| Team | Primary home ground | Other grounds | Coach | Captain | Overseas player | Refs |
| Essex | County Ground, Chelmsford | — |  Chris Silverwood |  Ryan ten Doeschate |  Neil Wagner  Mohammad Amir | |
| Hampshire | Rose Bowl, Southampton | — | Craig White | James Vince |  George Bailey | |
| Lancashire | Old Trafford, Manchester | — | Glen Chapple | Steven Croft |  Ryan McLaren | |
| Middlesex | Lord's, London | Merchant Taylors' School Ground, Northwood Uxbridge Cricket Club Ground, Uxbridge | Richard Scott | Adam Voges | Adam Voges | |
| Somerset | County Ground, Taunton | — | Matthew Maynard | Tom Abell | Dean Elgar | |
| Surrey | The Oval, London | Woodbridge Road, Guildford | Michael Di Venuto | Gareth Batty |  Kumar Sangakkara Aaron Finch | |
| Warwickshire | Edgbaston, Birmingham | — | Jim Troughton | Ian Bell | Jeetan Patel | |
| Yorkshire | Headingley, Leeds | North Marine Road Ground, Scarborough | Andrew Gale | Gary Ballance | Peter Handscomb |
Division Two
Team relegated from Division One| Team | Primary home ground | Other grounds | Coach | Captain | Overseas player | Refs |
| Derbyshire | County Ground, Derby | Queen's Park, Chesterfield | Kim Barnett | Billy Godleman | Jeevan Mendis Imran Tahir | |
| Durham | Riverside Ground, Chester-le-Street | — | Jon Lewis | Paul Collingwood | Stephen Cook Tom Latham | |
| Glamorgan | SWALEC Stadium, Cardiff | Penrhyn Avenue, Rhos-on-Sea St Helen's, Swansea |  Robert Croft | Jacques Rudolph | Jacques Rudolph | |
| Gloucestershire | County Ground, Bristol | College Ground, Cheltenham | Richard Dawson | Gareth Roderick | Cameron Bancroft Michael Klinger | |
| Kent | St Lawrence Ground, Canterbury | Kent County Cricket Ground, Beckenham Nevill Ground, Royal Tunbridge Wells | Matt Walker | Sam Northeast | Wayne Parnell Yasir Shah Adam Milne | |
| Leicestershire | Grace Road, Leicester | — | Pierre de Bruyn | Mark Cosgrove | Clint McKay | |
| Northamptonshire | County Ground, Northampton | — | David Ripley | Alex Wakely | Rory Kleinveldt | |
| Nottinghamshire | Trent Bridge, Nottingham | — | Peter Moores | Chris Read | James Pattinson | |
| Sussex | County Ground, Hove | Arundel Castle Cricket Club Ground, Arundel | Mark Davis | Luke Wright | Vernon Philander | |
| Worcestershire | New Road, Worcester | — | Steve Rhodes | Joe Leach | John Hastings |