Seaside Equity Partners is a San Diego-based private equity firm making control investments in providers of mission-critical services across the Western U.S. The firm targets skilled services (HVAC, plumbing, facility services), professional services (human capital, education, IT), and environmental services, partnering with founder- and family-led lower-middle-market companies.
80% of their portfolio is in Healthcare. Deal activity increased 100% year-over-year (2 deals in the last 12 months). Their most common stage is seed (80% of deals). Average disclosed round size is $11.0M (across 4 rounds with reported amounts).
Portfolio
5
Fund Size
$580M
Top Stage
Seed
Last 12 Mo
1
Team
Portfolio Breakdown
Stage Distribution
Sector Distribution
Investment Activity
DealsAvg Round Size
Portfolio
5 investments
| Company | Round | Amount | Date |
|---|---|---|---|
 Adaptyx Biosciences | Seed | $14M | Oct 2025 |
 Circulate Health | Seed | $12M | Jul 2025 |
 Somnee | Seed | — | Jun 2025 |
 Lifeforce | Series A | $12M | Jan 2023 |
 Paterna Biosciences | Seed | $6M | — |
Top Co-Investors
Khosla Ventures2 shared
SC Ventures1 shared
Time Ventures1 shared
Honeystone Ventures1 shared
Metalab Ventures1 shared
Ridgeline Partners1 shared
Peterson Ventures1 shared
Rosecliff1 shared
M131 shared
SpringTide1 shared
Divergent Capital1 shared
Interlagos1 shared
Cantos1 shared
Overwater Ventures1 shared
Stanford University1 shared
Hyperlink Ventures1 shared
Starbloom Capital1 shared
Last updated: 9 September 2026