32 Y Combinator companies in Defense, with team size, growth, open roles and funding.
Updated weekly, last on November 9, 2026. Roster from Y Combinator's public directory.
| Company | Batch | Team | 6 mo | 12 mo | Open roles | Total raised | Last round |
|---|---|---|---|---|---|---|---|
Stratospheric birds for defense | F25 | 73 | +46% | +143% | 5 | $650K | YC investment$500K, Dec 2025 |
Drone submarines | S25 | 35 | +30% | +59% | 0 | $6.5M | Seed$6.5M, Sep 2025 |
Counter Drone Systems. $1.6m sales. We delivered for the DoW. | X26 | 22 | +120% | +214% | 10 | $500K | YC investment$500K, Jun 2026 |
Query mission-critical video | W25 | 22 | +29% | +69% | 0 | $14.4M | Seed$7M, Mar 2026 |
Building The Next Generation of Night Vision Devices | W24 | 19 | +6% | +36% | YC | $6M | Series A$5.5M, Sep 2025 |
Rocket cargo delivery to contested environments | S26 | 16 | +23% | +33% | 2 | $11M | Seed$11M, Sep 2026 |
America's Golden Dome for Drones | S25 | 11 | +38% | YC | $6.5M | Seed$6M, Sep 2025 | |
Modular AI-Commanded Drones for Defence | W26 | 7 | YC | $500K | YC investment$500K, Apr 2026 | ||
Air-breathing hypersonics for scale. | F25 | 6 | +20% | YC | $500K | YC investment$500K, Dec 2025 | |
USA-made magnetics for robotics and defense. | S26 | 5 | 0 | $500K | YC investment$500K, Aug 2026 | ||
Making Defense Manufacturing Faster and Cheaper | S26 | 5 | YC | ||||
Submarine drones for defense | X26 | 5 | 0 | $500K | YC investment$500K, Jun 2026 | ||
Military exoskeletons | S26 | 4 | YC | Pre-seedAug 2026 | |||
Air Defense as a Service for Civilian Infrastructure. | S26 | 4 | YC | ||||
The hardware-agnostic operating system for drone defense | X26 | 4 | 0 | ||||
ApolloShield is a system that detects unwanted drones and drives them… | S16 | 4 | −20% | 0 | $2.6M | Seed$2.5M, Apr 2018 | |
Autonomous drones that fly and swim | F26 | 3 | 0 | ||||
Drone swarm defence at a small-unit level | S26 | 3 | 0 | ||||
Mass-deployable radars for air defense | S26 | 3 | YC | ||||
End-to-end Simulation for Defense Autonomy | F25 | 3 | 0 | $500K | YC investment$500K, Dec 2025 | ||
Precision navigation for UAVs operating without GPS. | F26 | 2 | 0 | ||||
Kill the drone, keep the jet. Reusable unmanned interceptors. | F26 | 2 | 0 | ||||
Track drones and missiles without radars - Accurate, Passive, Scalable | X26 | 2 | YC | ||||
Autonomous street sweeping as a service by retro-fitting vehicles | W21 | 2 | 0 | $230K | YC investment$125K, Apr 2021 | ||
Discover novel defense related materials/molecules. | F26 | 1 | 0 | ||||
Mass-produced AI strike systems and Counter-UAS | S26 | 1 | 0 | SeedAug 2026 | |||
Tankless Dive Gear - Breath Autonomy at Sea, Land & Space | W26 | 1 | 0 | $9M | Pre-seed$9M, Mar 2026 | ||
Anti-drone defense for the maritime domain | F26 | ||||||
AI-guided ballistic missiles, built for mass manufacturing | F26 | 0 | |||||
The highest performance modular battery packs for mobility/vehicles | F26 | YC | |||||
Building drone swarms that hunt hidden enemies. | S26 | ||||||
Air-gapped compute for defense contractors | X26 |
Every launched company in YC's public directory, with its batch, status, industry and location. New companies show up the week YC lists them.
Each company is matched to Crustdata by its website. Crustdata adds team size and its change over 6 and 12 months, open roles from job postings, reported funding, and founders' past employers.
Hiring the most counts distinct roles posted in the last 60 days. Growth needs 10+ people today, shrinking 20+ a year ago, so tiny teams do not top the lists. Rebuilt every week.
The numbers on this page come from three Crustdata API calls. Crustdata tags 5,000+ companies with Y Combinator as an investor; swap the filter for any investor, industry or headcount range and track your own list, with founders' work emails one call away.
# 1. every company with Y Combinator as an investor curl https://api.crustdata.com/company/search \ -H "authorization: Bearer $CRUSTDATA_API_KEY" \ -H "x-api-version: 2025-11-01" \ -d '{ "filters": { "field": "funding.investors", "type": "in", "value": ["Y Combinator"] }, "fields": ["basic_info.name", "headcount.total", "headcount.growth_percent", "funding.total_investment_usd"], "limit": 100 }' # 2. open listings per company, last 60 days (limit 0 = counts only) curl https://api.crustdata.com/job/search \ -H "authorization: Bearer $CRUSTDATA_API_KEY" \ -H "x-api-version: 2025-11-01" \ -d '{ "filters": { "op": "and", "conditions": [ { "field": "company.basic_info.company_id", "type": "in", "value": [...] }, { "field": "metadata.date_added", "type": "=>", "value": "2026-08-24" } ]}, "limit": 0, "aggregations": [{ "type": "group_by", "field": "company.basic_info.company_id", "agg": "count" }] }' # 3. the same company filter as a weekly watch: POST /watch/company/search
32 Y Combinator companies are in Defense; 32 are active.
3 companies posted roles in the last 60 days, led by 9 Mothers (10 roles), Icarus (5 roles) and Hop Aero (2 roles). 12 mark themselves as hiring on YC's directory.
By team growth over 6 months (10+ people): 9 Mothers (+120%), Icarus (+46%) and Perseus Defense (+38%).
Largest latest rounds in the last 12 months, after their YC batch: Hop Aero ($11M), DAIVIN! ($9M) and Conntour ($7M).