Mainsail Partners is a growth equity firm that invests in bootstrapped, founder-led B2B software and AI-enabled companies to help them scale and grow into market leaders. Founded in 2003, the firm has offices in San Francisco and Austin and has raised nearly $4 billion in committed capital across seven funds.
Their most common stage is growth (75% of deals). Average disclosed round size is $79.4M (across 8 rounds with reported amounts).
Portfolio
6
Fund Size
$1.5B
Top Stage
Growth
Last 12 Mo
0
Team
Portfolio Breakdown
Stage Distribution
Sector Distribution
Investment Activity
DealsAvg Round Size
Portfolio
8 investments
| Company | Round | Amount | Date |
|---|---|---|---|
| SSkimmer | Growth | $74M | Oct 2024 |
 Jobnimbus | Growth | $330M | Jan 2024 |
| Jobnimbus | Unknown | $53M | Jan 2021 |
| FFairWarning | Growth | $60M | Jun 2018 |
| SSteelwedge | Unknown | $22.5M | Jan 2017 |
| SSteelwedge | Growth | $22.5M | Jan 2015 |
 Resman | Growth | $36M | — |
 Apptega | Growth | $37M | — |
Top Co-Investors
Sumeru Equity Partners2 shared
Supply Chain Ventures2 shared
Verdane1 shared
Circadian Ventures1 shared
JAFCO Group Co., Ltd.1 shared
Globespan Capital Partners1 shared
Aspex Management1 shared
Last updated: 8 September 2026