Financing organisations of the USA:
Grants.gov — Portal for participants
https://www.grants.gov/web/grants/register.html
ERA Commons
eRA Commons Participant Portal
https://public.era.nih.gov/commons/public/login.do
European Commission Financing Schemes:
European Commission requires the coordinators to use Participant Portal
https://ec.europa.eu/research/participants/portal/desktop/en/home.html
Open grant offers of Horizon 2020 are reflected at CORDIS Open Calls.
https://ec.europa.eu/research/participants/portal/desktop/en/opportunities/h2020
Financing organisations of the UK:
Alzheimer Studies in the UK
https://a-r.org.uk/Login.aspx?ReturnUrl=%2findex.aspx
Alzheimer Society
https://grants.alzheimers.org.uk/Login.aspx?ReturnUrl=%2fIndex.aspx
Arthritis treatment in the UK
https://gt.arthritisresearchuk.org/login.aspx
Arts and Humanities Research Council (AHRC)
https://je-s.rcuk.ac.uk/JeS2WebLoginSite/Login.aspx
Biotechnology and Biological Sciences Research Council (BBSRC)
https://je-s.rcuk.ac.uk/JeS2WebLoginSite/Login.aspx
Bloodwise
https://grants.bloodwise.org.uk/Login.aspx
Breast Cancer Research Fund
https://grants.breastcancernow.org/Login.aspx?ReturnUrl=%2fIndex.aspx
British Academy
British Fund of Heart Diseases Study
British Medical Association
UK Cancer Research
UK Diabetes Research
https://grants.diabetes.org.uk/Login.aspx
Economic and Social Research Council (ESRC)
https://je-s.rcuk.ac.uk/Jes2WebLoginSite/login.aspx
Engineering and Physical Sciences Research Council (EPSRC)
https://je-s.rcuk.ac.uk/Jes2WebLoginSite/login.aspx
Kidney Disease Research
https://research.kidneyresearchuk.org/Login.aspx?ReturnUrl=%2f
Leverhulme Trust
https://grants.leverhulme.ac.uk/Login.aspx?ReturnUrl=%2fIndex.aspx
Medical Research Council (MRC)
https://je-s.rcuk.ac.uk/Jes2WebLoginSite/login.aspx
Multiple Sclerosis Society
https://research.mssociety.org.uk/Login.aspx?ReturnUrl=%2findex.aspx
Natural Environment Research Council (NERC)
https://je-s.rcuk.ac.uk/Jes2WebLoginSite/login.aspx
National Institute for Health Research (NIHR)
https://www.nihr.ac.uk/funding-opportunities/
Parkinson disease
https://research.parkinsons.org.uk/
Prostate cancer
https://grants.prostatecanceruk.org/Login.aspx?ReturnUrl=%2f
Royal Society
https://grants.royalsociety.org/
Science and Technology Facilities Council (STFC)
https://je-s.rcuk.ac.uk/Jes2WebLoginSite/login.aspx
Welcome Trust
https://wtgrants.wellcome.ac.uk/Login.aspx
Worldwide Cancer Research
https://grants.worldwidecancerresearch.org/Login.aspx?ReturnUrl=%2f