- Macmillan Cancer Information Centre
- Macmillan Cancer Support
- Macmillan Cancer Support Action Team
- Macmillan Direct Volunteering Services
- Macular Society
- Madrid In _ Language and Culture
- Make that Difference
- Make-A-Wish
- Making Music
- Malayalee Association of Reading Community
- Male Survivors Berkshire
- Mapis CIC
- Mapledurham Community Energy
- MAPPA (Multi-Agency Public Protection Arrangements)
- Marie Curie – Berkshire (Community Fundraising)
- Mary Seacole Day Nursery and Family Support Unit
- Me2 Club
- Mental Health Advocacy Service
- Mental Health Mates (MHM)
- MFM Reading 2 Transformation Centre
- Micklands Pre-School
- Micklands Primary School
- Mid Hants Railway Ltd Watercress Line
- Mills Archive Trust
- Mind in Berkshire (Buckinghamshire Mind)
- Mind in Berkshire (Oxfordshire Mind)
- Mind Shop (Reading)
- Missing Maps Reading
- MND Association – Reading and West Berkshire Branch
- Mo Farah Foundation
- Mobility Trust
- Monkeys Acting in Schools for Conservation (MASC)
- Motor Neurone Disease Association (Reading & West Berks)
- MS Society Reading Wokingham and Districts Group
- Muscular Dystrophy UK
- Museum of English Rural Life (MERL)
- Muslim Ladies Club UK
- My Cancer My Choices
- MyUmbrella LGBT+
