The Town Council is actively represented on a wide range of outside organisations.
| East Grinstead Town Twinning Association | Cllr Visser |
| Mid Sussex District Association of Parish Councils | Cllrs Mockford and Whittaker |
| Age UK East Grinstead and District | Cllr Hughes |
| Friends of East Grinstead Museum | Cllr Mockford |
| East Grinstead Music and Arts Festival | Town Mayor |
| Disability Access Group (East Grinstead and area) | Cllr Barnett |
| East Grinstead Business Association | Cllr Whittaker |
| East Grinstead Fairtrade Town Steering Group | Cllr Scott |
| Mid Sussex Association of Town Councils | Town Mayor, Leader of the Majority Group, Leader of the Minority Group and one other (Town Mayor, Cllrs Farren, Mockford and Whittaker) |
| Grenestede Talking News for the Blind | Cllr Peacock |
| Felbridge Beef and Faggott Trust | Cllr M Belsey |
| SANG Steering Group (MSDC) | Cllr Godwin & Reeves |
| East Grinstead Sport Council | Cllrs J Belsey & Whittaker |
| East Grinstead Food Bank | Cllr Peacock |
| Community Rail Partnership | Cllr Pond |
| Chequer Mead Arts & Community Trust | Cllr Barnett, Cllr Farren, Cllr Hughes and Cllr Mockford |