- Aava Mobile
- Aava Ohjelmistot
- Acament
- Action Squad Studios
- ActiveMEDI
- ADA Drive
- Add Inspiration
- AddSearch
- Adesante
- Aditux / Red Solution
- AdLaunch
- adlearning
- AdminLabs
- Adusso
- Advacam
- Aeromon
- Agendium
- Agilefant
- Ahkera
- Aibidia
- Aido
- Aid One
- Aikumo
- Aina Wireless
- Aino.io
- Airmodus
- AiScreen
- Aiven
- Alekstra
- Alien Snowboards
- Alinan Taito
- Almondella
- Almost Human
- Altal
- Altonova
- Altum Technologies
- Alula Energy
- Amandan Healthcare
- Ambronite
- Ampner
- Analyse²
- Analytics Cloud
- Anaxeos
- ANT Plant
- AnttiPatterns
- APE Payment
- Apifonica
- Aplagon
- Appchieve
- Apped
- AppFollow
- AppGyver
- Applixure
- Apprien
- Appstar
- Appstylist
- Aqsens
- Arctic Robotics
- Arctic Warriors
- Ardilla
- Arex Brokering Finland
- Arilyn
- Arkkeo
- Armada Interactive
- Artific Intelligence
- Artist Exchange
- Artome
- Arvo Mobile
- A.S.Helsingö
- Askpole
- Asqella
- Aste Finland
- Ateljee Amnelin
- Atol Avion
- Atomic Shapes
- Audiodraft
- Audrey
- Augmented Climbing Wall
- Augumenta
- Auntie
- Aurealis Pharma
- Aurelia Turbines
- AuroraXplorer
- AutoJerry
- Automarkkina