Can I see my girlfriend in Ramadan?

In islam there is no concept of Girl friend and Boy friend. Islam only allow simple wedding . After wedding you are allowed to see your wife in Ramadan. Because seeing a girl who is not mahram(a person with whom you cannot marry) to you , is a sin.

Can you see your partner during Ramadan?

The ultimate deed to be done during Ramadan is fasting, so a Muslim shouldnt bet anything on it. Put it this way: you can see your boyfriend or girlfriend anytime you want outside the time of Ramadan, but no one could guarantee that you can see Ramadan again the next year.