Sarah Friar
About Sarah Friar
Sarah Friar is Chief Financial Officer of OpenAI. She joined in June 2024 as its first CFO. Before that she was CEO of Nextdoor, which she helped take public in 2021 (NYSE: KIND).
Earlier she was CFO at Square, now Block. Square went public in 2015 while she was there. Before Square she was SVP of finance and strategy at Salesforce, and she held roles at Goldman Sachs and McKinsey. She grew up in Northern Ireland. She has an MEng from the University of Oxford and an MBA from Stanford GSB.
She sits on the boards of Walmart and Consensys, and has served on Slack's board. She co-founded Ladies Who Launch, a network for women entrepreneurs. She was granted an OBE in 2019 for services to entrepreneurship.
Public databases list about 8 to 9 personal investments, mostly seed and early-stage rounds from 2019 to 2026. PitchBook records a 2019 seed round in Belong and 2019 and 2020 rounds in Bond Financial Technologies. It also records 2021 and 2022 deals in Cloudsmith, Step, UNIPaaS and MedAll. PitchBook lists 2 exits.
The databases do not agree on every date, round and company, and most of them do not show her check sizes.
Her most recent recorded deal is Build, which was announced on June 30, 2026 as an $8.5M seed round led by Index Ventures. Pebblebed, Puzzle Ventures and Tiny.vc also took part. SiliconANGLE lists Friar among the angels in the round.
Build is a New York company. Its AI system, Dougie, automates industrial real estate development workflows such as site sourcing, technical due diligence, power assessment and early design.
We found no other public AI angel investments by her.
Her recorded deals are seed to Series C, mostly seed and early-stage rounds. Sectors include software, fintech, real estate services, education and training services, and retail. Tracxn lists the United Kingdom and the United States as her investment locations.
She has not publicly stated a thesis or check size that we could find. NFX Signal lists an investment range of $5K to $50K with a $25K sweet spot. That is a third-party listing, not a statement from Friar. Treat it as unconfirmed.
- Build: AI platform for industrial real estate development projects; $8.5M seed announced June 2026, led by Index Ventures.
- Cloudsmith: business software company; she is listed in its 2021 Series A.
- Belong: real estate services company; listed in a 2019 seed round and its March 2021 Series B.
- Bond Financial Technologies: software development company; listed in 2019 and 2020 rounds.
- MedAll: B2B education and training company; listed in its seed round in 2021 and 2022, depending on the source.
- Step: financial services company; listed in its April 2021 Series C.
- UNIPaaS: financial services company; listed in a 2021 deal.
- siliconangle.com/2026/06/30/build-raises-8-5m-accelerate-industrial-in
- linkedin.com/in/sarah-friar
- openai.com/index/openai-welcomes-cfo-cpo
- digitaleconomy.stanford.edu/person/sarah-friar
- pitchbook.com/profiles/investor/279754-03
- signal.nfx.com/investors/sarah-friar
- tracxn.com/d/people/sarah-friar/__jfq9bBBEZlxqNz7AJMJeWBrbE1rp3pffdfic
- crunchbase.com/person/sarah-friar
Investing activity
Sarah Friar appears in 1 AI deal tracked by the Lounge deals desk. The rounds are mostly Seed, with a median round size of $9M. The most recent is Build (Seed, $8.5M, Jun 2026).
Sarah Friar most often invests alongside Index Ventures, Transpose Platform Management, John Stecher and Tiny Supercomputer Investment Company, and the companies they back on Lounge are mostly in AI.
Deals
Frequently asked questions about Sarah Friar
Does Sarah Friar invest in AI startups as an angel?
Yes. She was one of the angels in Build's $8.5M seed round, announced in June 2026 and led by Index Ventures. We found no other public AI angel deals.
What is Sarah Friar's angel check size?
She has not publicly stated one. NFX Signal lists a $5K to $50K range with a $25K sweet spot, but this is a third-party listing and unconfirmed.
What stage does Sarah Friar invest in?
Her recorded deals are mostly seed and early-stage rounds, plus a few later rounds such as Belong's Series B and Step's Series C.
Who is Sarah Friar?
She is OpenAI's CFO and was previously CEO of Nextdoor and CFO of Square. She is on the boards of Walmart and Consensys.
How can founders contact Sarah Friar?
She is on LinkedIn and on X as @thefriley. We found no personal website or public pitch process, so a warm introduction through a shared investor or co-investor is the likelier route.
Is Sarah Friar an angel investor?
Yes. Sarah Friar invests personally as an angel.
What AI companies has Sarah Friar invested in?
Sarah Friar's AI investments include Build. The 1 round on Lounge are listed on this page with amounts, dates and co-investors.
What stage does Sarah Friar invest at?
In the rounds tracked on Lounge, Sarah Friar has invested at Seed, with a median round of $9M.
Who does Sarah Friar co-invest with?
Sarah Friar's most frequent co-investors on Lounge are Index Ventures (1 deal), Transpose Platform Management (1 deal), John Stecher (1 deal), Tiny Supercomputer Investment Company (1 deal) and Puzzle Ventures (1 deal).
How can founders reach Sarah Friar?
Founders on Lounge can see Sarah Friar's contact details in AI Investor Contacts (paid plans), check for a warm introduction through members who worked with them under Warm Paths, and add Sarah Friar to their Investor Pipeline to track the conversation.