Sean O’Sullivan – Startup Investor Profile

Sean O’Sullivan, Managing Partner at SOSV, focuses on pre-seed startup investments in human and planetary health globally. SOSV operates multi-stage investments through programs like IndieBio and HAX. Sean has a track record in founding and managing various companies, with experiences in real-time carpooling, leading humanitarian aid organizations, and pioneering the term ‘cloud computing.’ His partnership approach involves assessing market needs and engineering innovation. Geographically, SOSV has investments in the United States, Europe, Asia, and LATAM. Sean O’Sullivan holds a Bachelor’s degree in Electrical Engineering from Rensselaer Polytechnic Institute, a Master of Fine Arts in Film Production from the University of Southern California, and an Executive MBA from the University of Cambridge.

Location: Boston, MA

Country: Ireland

Investment Regions:

Investment Stages: pre-seed, seed

Website:

AI Reasoning: Searches on SOSV’s site and related pages show active investment activity in 2025 by SOSV under Sean O’Sullivan’s leadership; for example, SOSV announced program and fund activity in 2025 and has ongoing investments including portfolio companies such as those from IndieBio/HAX. The latest visible activity is within the past 6 months, so tag as very-active.

Low Activity – Only known angel investments more than 12 months ago.

Active – Known angel investments between the last 12 and 6 months.

Very Active – Known angel investments in the last 6 months.