Onam (IPA: [oːɳɐm]) is an annual Indian harvest festival celebrated predominantly by the Hindus of Kerala.^[1][2] A major annual event for Keralites, it is the official festival of the state^[1][3] and includes a spectrum of cultural events.^[4][5][1][6]

Various sections of Islam have raised concerns about the celebration of Onam by Muslims. However some Muslims observe Onam anyway, considering its celebrations and rituals as a cultural practice.^[7][8]

Ponmala Abdul Qadir Musliyar, secretary of Samastha Kerala Jem-iyyathul Ulama of AP Sunnis^[9] quotes the Ibn Hajar's view on Muslims participating in the celebration and non-celebratory activity exclusive to non-Muslims.^[10]

Since these are the signs of kufr (disbelief), it is indeed kufr if a Muslim does it imitating non-Muslims. On the other hand if doing it is with the only intention of participating in their celebration or the other (non-celebratory activity), without the intention of agreeing with signs of kufr, though it is not possible to judge he is a kafir, it is still sinful. If it happens unintentionally, without the intention of imitating or being similar to them anyway, one does not become a kafir for it nor does it become sinful.

Musliyar says that this Ibn Hajar's view itself is the ruling when a Muslim does something only done by non-Muslims and that the same applies to Muslims preparing special food on the festival day of non-Muslims. He also says that a Muslim would become a murthad (apostate) for lighting the nilavilak as a Hindu custom and that if Hindus' customs like lighting the nilavilak is done as an Indian custom, though the person does not become a murthad, it is still forbidden and sinful. Musliyar applies the same ruling on both lighting the nilavilak on public functions and breaking the coconut on public functions and adds that it is karahath^[11] to do them unintentionally (without having the intention of being similar to non-Muslims or participating in it at all). He says that lighting the nilavilak is not an Indian tradition and that inaugurating public functions by breaking the coconut or by the carrying of thalappoli is a Hindu custom and thus sinful.^[10]

Musliyar states the use of the nilavilak in Maqbaras is not imitation of the Hindus' custom. He explains that the nilavilak in Maqbaras is used solely for its material need while no special significance is given to it in the sense that it is a nilavilak.^[10]

He also says the following about being considered a kafir based on one's belief:^[10]

Similarly, performing sujood to the idol, wearing the poonul, wearing the rudraksha mala, lighting the lamp in front of an idol, a photo etc., are considered signs of hidden kufr (disbelief) in the heart. Because of doing these things, though one can say that one (the doer) is a kafir outwardly, but one will be a kafir in reality if one rejects what the rasul (Islamic prophet Muhammad) brought, in the heart.

The belt worn by Christian priests in the middle of their cassock, the Jews' cap, the Hindus' poonul etc., are external signs of kufr (disbelief); so the person who wears them is considered a kafir and dealt with him as a kafir. This is because such actions cannot stem from a person who fully accepts the prophet (Islamic prophet Muhammad). But if the prophet (Islamic prophet Muhammad) was fully accepted with the heart and apparently performed the signs of kufr (disbelief) for some other selfish interests, then he is not actually a Kafir in the sight of Allah (Shaikhzada 1/108, Hashiyyathunnihayah 1/113).  But according to Islamic Shari'ah, he is considered a kafir in the material world.

In 2019, Muslim religious speaker Simsarul Haq Hudawi, who completed graduation and postgraduation from Darul Huda Islamic University,^[12] affiliated to Samastha Kerala Jem-iyyathul Ulama of EK Sunnis, caused controversy over his statement that Muslims should not celebrate the festivals of other religions like Onam.^[13]

In 2016, a group of leaders from different organisations of EK Sunnis such as Sunni Mahal Federation, Samastha Kerala Jam-iyyathul Muallimeen, Sunni Yuvajana Sangham (SYS) and SKSSF has, in a joint statement, said that Islam forbids the following of rituals from other faiths.^[14]

A section of, Mujahids belonging to the Salafi movement, has opposed celebration of Onam and Christmas by Muslims.^[15] Muslim reformists have called on other Muslims to refrain from taking part in the festival.^[16] For example, a Kerala-based Mujahid^[17] Salafi preacher Shamsudheen Palath has called Onam as haram (wrong and forbidden).^[15]

A section of Muslims has expressed the view that Islam is both against celebrating and greeting non-Muslim religious celebration.^{[18][19][20][21]}

According to P.S. Salini, a research scholar in Islamic studies, most Muslims join the festivities with their friends and celebrate "Hindu festivals such as Onam".^[22] According to a 2001 chapter by Filippo Osella and Caroline Osella, both Hindus and non-Hindus have celebrated Onam equally "as a time when the unity of the family and kin group is particularly emphasized".^[23] In another 2008 paper, Osella and Osella state that "Onam is not celebrated by Muslims" and the Muslims who do prepare an Onam feast have an air of a "daring secret".^[24]

Some Muslim Indian politicians light a traditional vilakku (oil lamp), while others have refused to light such a lamp at Onam events declaring it to be a Hindu tradition and against the teachings of Islam. Muslim daily newspapers and other publications have condemned Muslim ministers who participate in Onam traditions.^[16][25][26]

• Sadya