- Aavagen
- Abomics
- Absentus
- Acament
- Action-Reaction Games
- Action Squad Studios
- ActiveMEDI
- ADA Drive
- Adaptos
- Add Inspiration
- AddSearch
- Adesante
- AdLaunch
- adlearning
- AdminLabs
- Adusso
- Advacam
- Advisus
- Aeromon
- Agendium
- Agilefant
- Aibidia
- Aido
- Aid One
- Aiforia Technologies
- Aikumo
- Ainak
- Aina Wireless
- Aino.io
- Airmodus
- AiScreen
- AISpotter
- Aito Intelligence
- Aiven
- AJR Solutions
- Akkurate
- Albert Welding
- Alien Snowboards
- Alinan Taito
- Almerin
- Almondella
- Almost Human
- Alphaville
- Altal
- Altonova
- Altum Technologies
- Alula Energy
- Amandan Healthcare
- Ambronite
- Amped
- Ampner
- Anaxeos
- Angular Velocity
- AnttiPatterns
- APE Payment
- Apifonica
- Appchieve
- Apped
- AppFollow
- AppGyver
- Applixure
- Apprien
- Appstar
- Appstylist
- Aquaminerals
- Arctic Robotics
- Arctic Security
- Arctic Warriors
- Ardilla
- Arex Brokering Finland
- Arilyn
- Arkkeo
- Armada Interactive
- Artific Intelligence
- Artist Exchange
- Artome
- Arvo Mobile
- A.S.Helsingö
- Asimos
- AskKauko
- Askpole
- Asqella
- Assetti
- Astalo Games
- Aste Finland
- Ateljee Amnelin
- Atol Avion
- Atomic Shapes
- Audiodraft
- AudioSauan
- Audrey
- Augmented Climbing Wall
- Augumenta
- Auntie
- Aurealis Pharma
- Aurelia Turbines
- Aurora Propulsion Technologies
- AuroraXplorer
- AutoJerry
- Autolle
- Automarkkina
- AutoVex
- Avanto Technologies
- Aves Netsec
- Axitare