For private grants, you may want to check the Foundation Center's Foundation Grants for Individuals Online. It's a subscription based website ($9.95 per month) but their opening blurb only says that the database is ideal for "students, ...
JustFund, a grantmaking platform built by funders and organizers of color, aims to revolutionize philanthropy by making it more equitable and efficient.
Business Grant Application Process | Personal Government Grants