That means that every second seat will be left unoccupied in a checkerboard pattern. Omniplex operates from 15 locations across Northern Ireland.
It is the latest in a series of measures aimed at combating the spread of Covid-19. Four new cases have been confirmed in NI, bringing the total to 16.
Paul John Anderson, director of Omniplex, said the move was in line with World Health Organisation guidance.”This means we’ve reduced our overall capacity by 50% and it will give cinemagoers peace of mind,” he said.
Mr Anderson said other measures include self-scanning of tickets, increased cleaning regimes and hand-sanitising stations in every cinema foyer.
Earlier on Tuesday, the first and deputy first ministers, Arlene Foster and Michelle O’Neill, announced they had cancelled plans to travel to Washington DC for St Patrick’s Day.
They said they took the decision to support ongoing efforts to deal with Covid-19.
“It’s regrettable we’re not able to go to the US but ultimately we’ve a call to make, we’ve a public health crisis on our hands and we need to make sure we’re here to respond,” said Ms O’Neill.
Northern Ireland Secretary Brandon Lewis is flying to Washington DC as planned to take part in a range of St Patrick’s Day events.