- Mail-forwarding business registration
- Maritime Greenwich World Heritage Site
- Markets
- Marriage
- Marriage - renewal of vows
- Marriage certificates
- Marriages - historical research
- Massage licence
- Mayor
- Meals on wheels
- Media enquiries
- Meetings of the Council
- Members of Parliament
- Members of the European Parliament
- Members of the London Assembly
- Memorials
- Mental health care
- Metro Centre
- Minutes, meetings and agendas
- Missed bin collections
- Mobile libraries
- Money worries
- Monuments
- Mortgage arrears advice
- MOT testing
- Museums and galleries
- Mutual exchange scheme
- Mystery shoppers