"Ik ben zo blij om jou te zien."
Translation:I am so happy to see you.
Blij zijn om is an idiomatic expression that means to be happy about something. In the above sentence om could be left out, and it would still be correct Dutch. Most native speakers will probably use blij om together in a sentence. Another example: Ik zal blij zijn om naar huis te gaan = I will be glad (happy) to go home.