Barry McElduff has been appointed as Steward and Bailiff of the Three Hundreds of Chiltern under Westminster’s arcane procedures for resigning MPs.
The move is part of the age-old formalities that give effect to the resignation of Members of Parliament.
When Sinn Féin president Gerry Adams quit Westminster in 2011 to run for the Irish parliament he was also granted a British aristocratic title - Crown Steward and Bailiff of the Manor of Northstead.
A statement from HM Treasury said: "The Chancellor of the Exchequer has this day appointed Barry McElduff to be Steward and Bailiff of the Three Hundreds of Chiltern."
A by-election date has yet to be set for his West Tyrone constituency. The onus is on Sinn Fein to propose a date for the electoral authorities. The agreed date will then be announced by the Speaker.
Mr McElduff resigned on Monday - 10 days after he posed with a Kingsmill-branded loaf on his head on the anniversary of the Kingsmill massacre.
The abstentionst MP, who had already been suspended by his party for three months, said staying in the job would have impeded efforts to forge reconciliation in Northern Ireland.
Mr McElduff has insisted that he had not meant the video as a reference to the sectarian murders of 10 protestant workmen by republican paramilitaries near the south Armagh village of Kingsmill in 1976.
However, he acknowledged the post had caused "deep and unnecessary hurt" to the Kingsmill families.
West Tyrone is a very safe Sinn Fein seat and the party will likely hold on to it in a future by-election.
There has been speculation that rival unionist parties could agree on a unity candidate, potentially from the victims sector, but even that move would be unlikely to see the republican party lose a seat it secured with 51% of the vote last year.