Guardsman Jatinderpal Singh Bhullar, 25, who joined the Scots Guards this year, has been given permission to wear a turban when on guard duty outside Buckingham Palace, breaking hundreds of years of tradition, Daily Mail reported Sunday.
The regiment traces its origin back to 1642 and its soldiers have worn bearskins on parade since 1832.
Mr Bhullar is based at Wellington Barracks in Birdcage Walk. The base is used by soldiers from the Scots Guards' F Company, who are responsible for public duties and guarding the Queen.
According to military sources, Mr Bhullar, from Birmingham, is expected to parade for the first time next week. When he marches with his colleagues he will become the first guardsman not to wear a bearskin headgear.
As a devout Sikh, it is mandatory for Mr Bhullar to wear a turban. It is intended to protect his hair, which he never cuts, and to keep them clean.
For centuries, Sikhs have worn turbans in battle and fought as part of the British Army - including Mr Bhullar's grandfather, who served in World War II.
The step, however, has irked some serving non-commissioned officers based at Wellington Barracks, who are furious that the Ministry of Defence (MoD) compromised centuries of history for one soldier.
Traditionalists in the Scots Guards say the allowances made for Mr Bhullar will make the whole company look ridiculous to tourists and onlookers.
Mr Bhullar is one of only 20 to 25 British-born Sikhs in the British Army.
An MoD spokeswoman said: "The Army takes great pride in its diversity. Discussions are underway between this unit, the Sikh community and the MoD. The individual will have the full support of the Army and his colleagues."