Plans to convert an old warehouse and offices in Vicarage Place, Caldmore, into a place of worship were approved at a recent Walsall Council planning meeting.
The approval came despite dozens of people lodging objections and the authority receiving two petitions.
The planning application was lodged by the Ahmadiyya Muslim Association UK.
Dr Azher Siddiq, chair of the association's Walsall branch, said: "From my point of view, we are delighted we have had our planning application accepted.
"We would like to reassure all members of the local community that we are a progressive, forward thinking and peaceful organisation who are only concerned with doing good for others.
"We place huge importance on serving the local community who we live with and we hope to be a force for good in Walsall.
"I look forward to building our relationship with the community in Caldmore and as president of the Walsall branch, I am happy to enter into a dialogue with anyone at any time regarding concerns they may have."
A government planning inspector ruled the site suitable for a place of worship, following a previous application at the same site.
An initial motion to refuse the application due to the impact on community cohesion, lack of parking, the impact on residents and fear of crime, was made by Councillor Aftab Nawaz.
Despite attempts to see the plans thrown out, councillors voted in majority to approve the application.
The application had seen dozens of people lodge objections with the council and two petitions, signed by more than 50 people, were handed in.
The Ahmadiyya Muslim Association UK said it expected between 10 and 30 worshippers to attend the mosque on average per day, rising to between 50 and 60 on Fridays.
Dr Siqqiq also spoke of his disbelief that it would be considered the application would do any harm to community cohesion, based on the history of his group.
He said: "We are a peace loving community, with 15 sites across the country, none of which has any history of prompting any kind of disorder, in fact the opposite is true.
"We work with charity's at a local and national level and have a great reputation within the communities we are already based."