| Inns | HS |
| 240-3 | 91 | Glamorgan v Surrey | The Kia Oval, Kennington | 2015 |
| 235-6 | 87 | Glamorgan v Sussex | The 1st Central County Ground, Hove | 2024 |
| 222-6 | 69 | Glamorgan v Surrey | The Kia Oval, Kennington | 2025 |
| 220-6 | 65 | Glamorgan v Essex | Ambassador Cruise Line Ground, Chelmsford | 2025 |
| 219-5 | 50 | Glamorgan v Sussex | The 1st Central County Ground, Hove | 2023 |
| 216-5 | 45 | Glamorgan v Hampshire | Sophia Gardens, Cardiff | 2019 |
| 206-6 | 74 | Glamorgan v Somerset | County Ground, Taunton | 2006 |
| 201-6 | 77* | Glamorgan v Gloucestershire | Sophia Gardens, Cardiff | 2018 |
| 199-4 | 72 | Glamorgan v Middlesex | The SWALEC Stadium, Cardiff | 2011 |
| 199-2 | 77* | Glamorgan v Kent | Spitfire Ground, St Lawrence, Canterbury | 2017 |
| 198-7 | 89 | Glamorgan v Essex | Sophia Gardens, Cardiff | 2018 |
| 196-4 | 78 | Glamorgan v Worcestershire | Blackfinch New Road, Worcester | 2020 |
| 195-6 | 58 | Glamorgan v Surrey | The Kia Oval, Kennington | 2018 |
| 193-7 | 49* | Glamorgan v Somerset | Sophia Gardens, Cardiff | 2003 |
| 192-3 | 89 | Glamorgan v Essex | The Ford County Ground, Chelmsford | 2010 |
| 192-4 | 75* | Glamorgan v Surrey | The Kia Oval, Kennington | 2014 |
| 191-3 | 63* | Glamorgan v Kent | Sophia Gardens, Cardiff | 2023 |
| 190-5 | 77 | Glamorgan v Gloucestershire | Sophia Gardens, Cardiff | 2006 |
| 190-5 | 51* | Glamorgan v Kent | Spitfire Ground, St Lawrence, Canterbury | 2022 |
| 189-6 | 68 | Glamorgan v Essex | The Essex County Ground, Chelmsford | 2014 |
| 189-6 | 63* | Glamorgan v Gloucestershire | Seat Unique Stadium, Bristol | 2025 |
| 188-4 | 99* | Glamorgan v Gloucestershire | Sophia Gardens, Cardiff | 2020 |
| 186-5 | 51 | Glamorgan v Worcestershire | County Ground, New Road, Worcester | 2005 |
| 186-9 | 51 | Glamorgan v Somerset | Sophia Gardens, Cardiff | 2006 |
| 186-5 | 46* | Glamorgan v Sussex | County Ground, Hove | 2010 |
| 185-7 | 97* | Glamorgan v Essex | The Cloud County Ground, Chelmsford | 2022 |
| 185-4 | 93 | Glamorgan v Essex | Sophia Gardens, Cardiff | 2025 |
| 184-4 | 78 | Glamorgan v Hampshire | The Ageas Bowl, Southampton | 2021 |
| 184-9 | 49 | Glamorgan v Middlesex | Sophia Gardens, Cardiff | 2025 |
| 183-8 | 68* | Glamorgan v Somerset | Sophia Gardens, Cardiff | 2005 |
| 183-8 | 98 | Glamorgan v Northamptonshire | County Ground, Northampton | 2008 |
| 183-6 | 66 | Glamorgan v Somerset | The Cooper Associates County Ground, Taunton | 2017 |
| 183-8 | 39 | Glamorgan v Surrey | Sophia Gardens, Cardiff | 2018 |
| 183-5 | 60* | Glamorgan v Gloucestershire | Sophia Gardens, Cardiff | 2023 |
| 183-7 | 61* | Glamorgan v Sussex | Sophia Gardens, Cardiff | 2024 |
| 182-8 | 44 | Glamorgan v Gloucestershire | County Ground, Bristol | 2021 |
| 182-8 | 47 | Glamorgan v Essex | Sophia Gardens, Cardiff | 2024 |
| 181-7 | 77 | Glamorgan v Hampshire | The Ageas Bowl, Southampton | 2015 |
| 181-6 | 76 | Glamorgan v Surrey | The Kia Oval, Kennington | 2017 |
| 181-9 | 35 | Glamorgan v Somerset | The Cooper Associates County Ground, Taunton | 2018 |
| 181-7 | 58 | Glamorgan v Surrey | Sophia Gardens, Cardiff | 2024 |
| 180-5 | 57 | Glamorgan v Somerset | Sophia Gardens, Cardiff | 2019 |
| 179-5 | 65* | Glamorgan v Sussex | The SWALEC Stadium, Cardiff | 2014 |
| 179-7 | 53* | Glamorgan v Kent | The Nevill Ground, Tunbridge Wells | 2015 |
| 178-5 | 85 | Glamorgan v Somerset | County Ground, Taunton | 2012 |
| 177-7 | 54 | Glamorgan v Kent | The SWALEC Stadium, Cardiff | 2014 |
| 177-7 | 67 | Glamorgan v Middlesex | Lord's Cricket Ground, St John's Wood | 2024 |
| 176-3 | 96* | Glamorgan v Somerset | County Ground, Taunton | 2014 |
| 176-5 | 51 | Glamorgan v Gloucestershire | Brightside Ground, Bristol | 2017 |
| 176-7 | 56 | Glamorgan v Somerset | The Cooper Associates County Ground, Taunton | 2025 |
| 175-4 | 97* | Glamorgan v Kent | The SSE SWALEC Stadium, Cardiff | 2016 |
| 175-9 | 93* | Glamorgan v Gloucestershire | Sophia Gardens, Cardiff | 2021 |
| 175 | 48 | Glamorgan v Essex | Sophia Gardens, Cardiff | 2023 |
| 175-6 | 43 | Glamorgan v Essex | The Cloud County Ground, Chelmsford | 2023 |
| 174-4 | 69* | Glamorgan v Warwickshire | Edgbaston, Birmingham | 2006 |
| 174-5 | 68* | Glamorgan v Somerset | County Ground, Taunton | 2007 |
| 174-4 | 52 | Glamorgan v Sussex | Sophia Gardens, Cardiff | 2019 |
| 173-5 | 68 | Glamorgan v Warwickshire | Edgbaston, Birmingham | 2012 |
| 173-4 | 81* | Glamorgan v Sussex | Sophia Gardens, Cardiff | 2018 |
| 173-5 | 65 | Glamorgan v Surrey | The Kia Oval, Kennington | 2022 |
| 173-7 | 37 | Glamorgan v Somerset | The Cooper Associates County Ground, Taunton | 2022 |
| 172-5 | 78* | Glamorgan v Surrey | The Brit Oval, Kennington | 2010 |
| 172-4 | 64 | Glamorgan v Gloucestershire | Brightside Ground, Bristol | 2016 |
| 172-5 | 58 | Glamorgan v Gloucestershire | Sophia Gardens, Cardiff | 2019 |
| 172-2 | 89 | Glamorgan v Middlesex | Sophia Gardens, Cardiff | 2022 |
| 172 | 40 | Glamorgan v Sussex | Sophia Gardens, Cardiff | 2025 |
| 171 | 70 | Glamorgan v Essex | The Essex County Ground, Chelmsford | 2015 |
| 171-5 | 65* | Glamorgan v Somerset | The SSE SWALEC Stadium, Cardiff | 2017 |
| 171-8 | 60* | Glamorgan v Essex | The Cloudfm County Ground, Chelmsford | 2018 |
| 171-8 | 76 | Glamorgan v Surrey | Sophia Gardens, Cardiff | 2023 |
| 171 | 71 | Glamorgan v Somerset | Sophia Gardens, Cardiff | 2023 |
| 170-4 | 72 | Glamorgan v Worcestershire | Sophia Gardens, Cardiff | 2003 |
| 170-7 | 45 | Glamorgan v Warwickshire | Edgbaston, Birmingham | 2007 |
| 170-5 | 43 | Glamorgan v Somerset | The SWALEC Stadium, Cardiff | 2008 |
| 170-5 | 76* | Glamorgan v Somerset | County Ground, Taunton | 2008 |
| 170-4 | 96 | Glamorgan v Somerset | County Ground, Taunton | 2015 |
| 170-8 | 53 | Glamorgan v Middlesex | Brunton Memorial Ground, Radlett | 2021 |
| 169-5 | 60 | Glamorgan v Middlesex | The SSE SWALEC Stadium, Cardiff | 2015 |
| 168-7 | 69 | Glamorgan v Gloucestershire | County Ground, Bristol | 2003 |
| 168-6 | 38* | Glamorgan v Hampshire | The Ageas Bowl, Southampton | 2018 |
| 168 | 51 | Glamorgan v Sussex | Sophia Gardens, Cardiff | 2021 |
| 168 | 38 | Glamorgan v Middlesex | Brunton Memorial Ground, Radlett | 2022 |
| 167-3 | 63* | Glamorgan v Middlesex | The SWALEC Stadium, Cardiff | 2010 |
| 167-7 | 63 | Glamorgan v Surrey | The Kia Oval, Kennington | 2011 |
| 167-9 | 38 | Glamorgan v Gloucestershire | College Ground, Cheltenham | 2018 |
| 166-5 | 43* | Glamorgan v Northamptonshire | County Ground, Northampton | 2004 |
| 166-6 | 52 | Glamorgan v Gloucestershire | The SWALEC Stadium, Cardiff | 2009 |
| 166-8 | 47 | Glamorgan v Somerset | County Ground, Taunton | 2011 |
| 166-8 | 74 | Glamorgan v Surrey | The Kia Oval, Kennington | 2021 |
| 166-8 | 52 | Glamorgan v Essex | The Cloud County Ground, Chelmsford | 2024 |
| 165-9 | 41 | Glamorgan v Warwickshire | Edgbaston, Birmingham | 2005 |
| 164-3 | 63 | Glamorgan v Worcestershire | Sophia Gardens, Cardiff | 2006 |
| 164-8 | 76 | Glamorgan v Surrey | The SWALEC Stadium, Cardiff | 2010 |
| 164-6 | 38 | Glamorgan v Hampshire | The SWALEC Stadium, Cardiff | 2014 |
| 164-7 | 63* | Glamorgan v Sussex | The Brighton and Hove Jobs County Ground, Hove | 2015 |
| 164 | 65 | Glamorgan v Warwickshire | Edgbaston, Birmingham | 2017 |
| 162-7 | 43 | Glamorgan v Gloucestershire | Sophia Gardens, Cardiff | 2004 |
| 162-5 | 42 | Glamorgan v Gloucestershire | County Ground, Bristol | 2006 |
| 162-8 | 47 | Glamorgan v Gloucestershire | Seat Unique Stadium, Bristol | 2023 |
| 162-8 | 57 | Glamorgan v Sussex | Sophia Gardens, Cardiff | 2023 |
| 161-5 | 74 | Glamorgan v Warwickshire | Sophia Gardens, Cardiff | 2004 |
| 161-5 | 59 | Glamorgan v Worcestershire | The SWALEC Stadium, Cardiff | 2013 |
| 161-7 | 34 | Glamorgan v Hampshire | The Ageas Bowl, Southampton | 2014 |
| 160-6 | 40 | Glamorgan v Northamptonshire | County Ground, Northampton | 2006 |
| 160-9 | 44 | Glamorgan v Somerset | Sophia Gardens, Cardiff | 2018 |
| 160-7 | 58 | Glamorgan v Northamptonshire | Edgbaston, Birmingham | 2020 |
| 159-4 | 57 | Glamorgan v Worcestershire | County Ground, New Road, Worcester | 2013 |
| 159-8 | 81 | Glamorgan v Sussex | The SSE SWALEC Stadium, Cardiff | 2016 |
| 158-8 | 68 | Glamorgan v Gloucestershire | Sophia Gardens, Cardiff | 2022 |
| 157-2 | 71 | Glamorgan v Essex | The SWALEC Stadium, Cardiff | 2014 |
| 157-8 | 49 | Glamorgan v Surrey | The Kia Oval, Kennington | 2023 |
| 156-3 | 54 | Glamorgan v Somerset | The SSE SWALEC Stadium, Cardiff | 2016 |
| 156-3 | 65 | Glamorgan v Essex | Sophia Gardens, Cardiff | 2021 |
| 155-9 | 40 | Glamorgan v Northamptonshire | County Ground, Northampton | 2009 |
| 155-2 | 71* | Glamorgan v Hampshire | Sophia Gardens, Cardiff | 2018 |
| 154-6 | 46 | Glamorgan v Northamptonshire | The SWALEC Stadium, Cardiff | 2008 |
| 154-5 | 65 | Glamorgan v Kent | The SWALEC Stadium, Cardiff | 2011 |
| 153-7 | 38 | Glamorgan v Gloucestershire | County Ground, Bristol | 2010 |
| 153-7 | 47 | Glamorgan v Northamptonshire | County Ground, Northampton | 2013 |
| 153-6 | 41* | Glamorgan v Surrey | Sophia Gardens, Cardiff | 2021 |
| 153-3 | 63* | Glamorgan v Sussex | The 1st Central County Ground, Hove | 2022 |
| 153 | 42 | Glamorgan v Somerset | The Cooper Associates County Ground, Taunton | 2023 |
| 152-6 | 41 | Glamorgan v Surrey | Sophia Gardens, Cardiff | 2019 |
| 152 | 63 | Glamorgan v Somerset | The Cooper Associates County Ground, Taunton | 2019 |
| 151 | 51 | Glamorgan v Warwickshire | St Helen's, Swansea | 2005 |
| 151-4 | 55* | Glamorgan v Gloucestershire | County Ground, Bristol | 2009 |
| 151-4 | 54 | Glamorgan v Gloucestershire | The SWALEC Stadium, Cardiff | 2010 |
| 151-7 | 46 | Glamorgan v Surrey | The SWALEC Stadium, Cardiff | 2011 |
| 151-8 | 62 | Glamorgan v Sussex | The Brighton and Hove Jobs County Ground, Hove | 2014 |
| 151-6 | 57 | Glamorgan v Sussex | Sophia Gardens, Cardiff | 2022 |
| 151 | 77 | Glamorgan v Middlesex | Sophia Gardens, Cardiff | 2023 |
| 150-7 | 51* | Glamorgan v Gloucestershire | County Ground, Bristol | 2020 |
| 150-9 | 75 | Glamorgan v Middlesex | Sophia Gardens, Cardiff | 2021 |
