All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
The parents have no right to force their son to marry someone whom he does not like, however, the son should be wise and soft in dealing with them; for more benefit, please refer to Fatwa 86777.
Marrying a woman against the will of the parents is a serious matter and has unpleasant consequences on the future of the marital life and on the children who may come from this marriage. Therefore, it is more appropriate to convince the parents and not follow one's emotions which may fade away or change. Moreover, marrying a specific woman is not a reason by itself for angering and saddening the parents. For more benefit in this regard, please refer to Fatwa 83379.
To conclude, your marriage to that girl would be correct marriage, however, it is better to inform your parents as a sign of being kind and dutiful to them, and you should try to convince them until they accept it.
Nonetheless, if it is impossible for your parents to accept this marriage, then it is more appropriate to avoid marrying this girl because the obedience of the parents comes in priority over marrying a specific woman.