Yes, according to Islamic tradition, you will have a spouse in Jannah, even if you were unmarried in this life.
Islamic sources indicate that no one will remain single in Paradise. If you did not have a spouse in this life (dunya), you will be given a spouse in Jannah. This is based on the understanding that Paradise is a place of complete fulfillment and contentment, and companionship is a part of that. Therefore, the concept of a "soulmate" can be understood as being fulfilled through the companionship you will have in Jannah. This fulfillment may come through a spouse granted to you there.
It's important to note that while the concept of a "soulmate" isn't explicitly mentioned in Islamic texts, the idea of finding complete happiness and companionship in Jannah aligns with the broader Islamic understanding of Paradise as a place of perfect bliss.