Each of the six counties across North Wales now has at least one testing site, open seven-days-a-week and with some operating from 8am-8pm.
Teresa Owen, Executive Director of Public Health at Betsi Cadwaladr University Health Board, urged people to book an appointment at their nearest centre if they are showing symptoms of COVID-19.
She also backed the Welsh Government's Help Us, Help You campaign, encouraging members of the public to correctly access NHS services and not turn up at emergency departments with ailments that could have been treated by a GP, pharmacist or minor injuries unit.
Teresa Owen said: "By rolling out test centres across North Wales we have improved accessibility and ease of use for residents concerned they may have the virus.
"COVID-19 is still circulating in our communities, so it is vital – especially over the winter months – that anyone experiencing symptoms self isolates immediately and books a test.
"There are facilities available to drive in or come on foot, but they are only open to people who have an appointment, wearing a face covering and following instructions from staff on-site.
"We want everyone to have as safe and normal as Christmas as possible. It has been a challenging year and we can continue to all play our part by washing our hands, social distancing and adhering to the COVID-19 restrictions."
There are Community Testing Units (CTU), Mobile Testing Units (MTU), Local Testing Sites (LTS) and Regional Testing Sites (RTS) in North Wales. They are:
Symptoms of COVID-19 include a new continuous cough, a high temperature and a loss of or change to sense of smell or taste.
The test involves taking a swab of the inside of your nose and the back of your throat, using a long cotton bud, and results will usually be received within 72 hours.
Contact tracing will continue throughout the festive period, therefore people may be contacted over weekends and Bank Holidays.
For a full list of Covid-19 test sites, times and information, click here.
To book a test, call 119 or visit: www.gov.wales/getting-tested-coronavirus-covid-19
For more on the Help Us, Help You campaign, follow the hashtags #HelpuNiHelpuChi and #HelpUsHelpYou on social media.