Valentine's day Halal or Haram in Islam

History of Valentine's day
     Christians celebrate Valentine's day in the memory of 3rd century Roman Saint known as Saint Valentine who was sentenced to death on 14 February 270 CE.


Valentine's day in Islam
A Muslim may not celebrate or participate in a non-Muslim festival. Celebration or participation may indicate an endorsement of such an occasion and its principle. Celebrations are characteristic of groups and, as Muslims, we have our own celebrations and festivals. Also, imitating a group may render one to be a member of such a group. Hence, as Muslims, we should treat Valentine's Day as any other day and do nothing special whatsoever on this day.
The scholars have issued fatwas stating that it is haraam to celebrate Valentine’s Day.

1 –Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) was asked about Valentine's day.
He replied:
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).

Quranic Verses and Hadith
In Quran Allah says that

"O you who have believed, do not take the Jews and the Christians as allies. They are [in fact] allies of one another. And whoever is an ally to them among you - then indeed, he is [one] of them. Indeed, Allah guides not the wrongdoing people."
[Quran 5:51]

Hadith
Anas, may Allah be pleased with him, said: “When the Prophet sallallaahu `alayhi wa sallam ( may Allah exalt his mention ) went to Madinah, he found that they had a couple of days of celebration; so, he said:

 ‘When I came, you had two days during which you amused yourselves and Allah The Almighty has granted you instead of these days, two better ones: the day of Al-Fitr (‘Eed after Ramadan) and the day of An-Nahr (‘Eed during Hajj (major pilgrimage) on 10th of Thul-Hijjah).’”

 [Abu Daawood, An-Nasaa’i, Saheeh]
Al-Haafith Ibn Hajar may Allah have mercy upon him said: "This Hadeeth indicates that it is disliked to celebrate non-Muslim holidays or to imitate them.