MAINSAIL PARTNERS
MAINSAIL PARTNERS is a Series A, Series B and Series C+ fund in the US and Canada writing $10M–$50M checks into Enterprise, Healthcare, vertical-saas, financial-tech, infrastructure-software, security-software and healthcare-it.
- Stages
- Series A, Series B, Series C+
- Sectors
- Enterprise, Healthcare, vertical-saas, financial-tech, infrastructure-software, security-software, healthcare-it
- Check size
- $10M–$50M
- Invests in
- US-wide, Canada
- Actively investing
- Yes
- Founded
- 2003
- Assets under management
- $4B+
- Website
- mainsailpartners.com
Thesis
Mainsail Partners is a growth equity firm founded in 2003 that focuses on partnering with bootstrapped, founder-led business-to-business (B2B) software companies in the United States and Canada. Their investment strategy centers on scaling companies that have achieved growth without external capital, with a particular emphasis on vertical SaaS, financial technology, healthcare IT, infrastructure and security software, and select horizontal SaaS. Mainsail Partners VII closed at $1.535 billion in May 2025, bringing the firm's total capital commitments to nearly $4 billion. The firm typically invests $10 million to $50 million per transaction and focuses on companies poised for growth that require strategic support. Their investment stage preference leans towards growth equity, focusing on companies that are already generating revenue and have demonstrated a path to profitability, with significant investments in Series B and Series C rounds. They also invest in Series A rounds.
Common questions
Does MAINSAIL PARTNERS invest at the Series A stage?
Yes. MAINSAIL PARTNERS lists Series A, Series B and Series C+ among the stages it invests in.
What check size does MAINSAIL PARTNERS write?
MAINSAIL PARTNERS writes $10M–$50M checks.
Where does MAINSAIL PARTNERS invest?
MAINSAIL PARTNERS invests in the US and Canada.