Valentine’s Day is a Jaahili Roman festival, which continued to be celebrated until after the Romans became Christian.
Celebrating Valentine’s Day is not permissible for a number of reasons.
1- It is an innovated festival for which there is no basis in Islam.
2- It promotes love and infatuation.
3- It calls for hearts to be preoccupied with foolish matters that are contrary to the way of the righteous salaf (may Allaah be pleased with them).
It is not permissible on this day to do any of the things that are characteristic of this festival, whether that has to do with food, drinks, clothing, exchanging gifts or anything else.
End quote from Majmoo’ Fataawa
Al-Shaykh Ibn ‘Uthaymeen (16/199)