The polls are open until 10.30pm tonight.
It's voting day in the first Dáil election in Ireland since the start of the pandemic.
Voters in Dublin Bay South will cast ballots to elect a replacement for former Fine Gael minister Eoghan Murphy.
Our Political Correspondent Seán Defoe reports:
"Ballot boxes open at the earlier-than-usual time of 7am this morning and will stay open until 10.30pm tonight, allowing more time for voting so people can space out when they arrive.
There are some changes to the typical election day due to Covid-19.
People in Dublin Bay South are asked not to vote if they're displaying Covid symptoms or are self-isolating.
Facemasks need to be worn in polling centres - and people are asked to bring their own pens or pencils to mark their ballots.
Photo ID will also be needed - and staff may ask people to briefly remove your mask to confirm identity.
There may be socially distant queues at busier times and people are asked to plan their voting for quieter periods.
All polling stations will be cleaned and sanitised every two and a half hours.
There's 15 candidates on the ballot for this by-election.
The votes will be moved to the RDS when ballot boxes close - with the count starting at 9am tomorrow morning."

Sharp Rise In M9 Collisions With Garda Call-Outs Up Year-On-Year
Councillor Seeks Clarity On How Often Nightclubs and Late Bars In Naas Are Inspected For Fire Risks
New Figures From CSO Reveal How Much International Protection Applicants Earn Compared To Average Worker In Ireland
Unpaid Eight-Month Work And Training Placement For Adults With Disabilities Branded "Extremely Unfair"
Department Of Education Defends Kildare SNA Cuts Amid Claims Of Reduced Need At Some Schools
Naas Nurses Threaten Escalation As Staffing Row Deepens
Driving Tests Face Disruption As RSA Testers To Strike Next Week
Jury Delivers Not Guilty By Reason Of Insanity Verdict In Ballyfin Demesne Strangling Case