Residents of Kilburn Ward in Brent will elect a new Brent Council representative on Thursday 5 May 2016, following the death of Cllr Tayo Oladapo.
The by-election will take place on the same day as the Mayor of London and London Assembly elections.
The deadline for nominations to stand in the Kilburn by-election is 4pm on Thursday 7 April 2016, and a full list of candidates will be published by Friday 8 April.
Currently 10,719 people are registered to vote in the by-election, but anyone who is not yet registered has until midnight on Monday 18 April 2016, to do so.
Carolyn Downs, Returning Officer and Chief Executive at Brent Council, said: "Having the Kilburn by-election on the same day as the Mayor of London and London Assembly elections means less hassle for residents in having to turn out and vote on different days, while at the same time keeping cost to the public purse to a minimum.
"Voting is both a democratic right and a civic responsibility too, so I'd encourage anyone who is eligible but not yet registered to vote, to make sure they do so before the deadline."
Residents who want to cast their vote by post at the by-election, who are not already registered as postal voters, need to submit their application by 5pm on Tuesday 19 April 2016.
Voters who are unable to attend a polling station also have the option to appoint a proxy to vote on their behalf. Applications for a proxy vote must be submitted by 5pm on Tuesday 26 April 2016.