United States · 
Who invested in Mill?
Mill's investors include Google Ventures, Breakthrough Energy, Lowercarbon Capital, Fifth Wall and Energy Impact Partners.
20242025
$70MSeries C?Venture
United States · Venture startup
Who invested in Mill
Funding summaryUpdated 26 Oct 2026
$70Mraised across 2 rounds since 2023, from 2 sources
- Latest round
- VentureDec 2025
- Biggest round
- $70MSeries C · Sept 2023
- Investors
- 5
The funding story
Each circle is a round, placed by date and sized by amount. The line above is the running total.
- First round
- Series C, $70M Sept 2023
- Biggest round
- $70M Series C · Sept 2023
- Between rounds
- 2.3 years from the last two
The rounds
- Dec 2025VentureAmount undisclosed4 returning
Source recorded
- Sept 2023Series C$70M5 new
Source recorded
Who was in which round
The busiest backers across the latest rounds. A filled square is a round they joined; a dark one, a round they led.
Series C2023Venture2025
Google Ventures
Breakthrough Energy
Lowercarbon Capital
Fifth Wall
Energy Impact Partners
Google VenturesBreakthrough EnergyLowercarbon CapitalFifth WallEnergy Impact PartnersEveryone who backed them
Missing a round, or an investor who was in one? Tell us.
Also claim to have backed them
These 5 firms list Mill as a portfolio company on their own websites, but no report of a round names them. They are the firms' own claims, kept apart from the rounds above.
Quick answers about Mill
How much has Mill raised?
Mill has raised $70M across 2 rounds since 2023. One round did not disclose an amount, so the total is a floor.
When did Mill last raise?
Mill's most recent round was a Venture in Dec 2025.
What was Mill's biggest round?
Mill's largest round on record is $70M (Series C), in Sept 2023.
Who backed Mill first?
Mill's first round on record, in Sept 2023, was backed by Google Ventures, Breakthrough Energy and Lowercarbon Capital and 2 others.
What stage is Mill at?
Mill's latest named round is a Venture, in Dec 2025.
Where is Mill based?
Mill is based in the United States.
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