Those opposed raised concerns about issues of Christian faith, it providing an additional day of rest for workers and whether in practice workers would be able to genuinely choose not to work on Easter Sunday.
After a hearing in December, where one submitter who was for the policy and one who was against spoke, the council deliberated and decided to adopted the policy on Thursday.
Northland Chamber of Commerce chief executive Steve Smith said the adoption of the policy meant freedom for Whangārei businesses.
He said it gave business owners flexibility to decide their trading hours.
"Some smaller businesses may opt not to open because lifestyle is important and they may want to go fishing, too."
Smith said he had already received calls thanking the chamber for its support in "getting this across the line".
In regards to workers genuinely being able to choose not to work, he expected businesses would respect that.
"Employees have rights which should be protected ... largely, the majority of people out there will be reasonable."
As for how many shops would take advantage of the rule this Easter, he said it depended entirely on the industry they were in, for example, those servicing visitors to Whangārei would likely open.
A submission from St Andrews Church stated no trading should take place on Easter Sunday and all businesses should be closed to celebrate and commemorate the resurrection of Christ from the dead.
"In a Christian country the population should respect the importance of the day with the Christian believers that actively celebrate and commemorate this day."
Whangārei is the last of the three district councils in Northland to adopt a policy to allow shops to open on Easter Sunday.
Kaipara and Far North have had Easter Sunday policies in place for a couple of years.
