The "NZ made" Facebook page was created about a month ago and already has nearly 450,000 followers - with the number still growing.
Sarah Colcord, who started the page, told RNZ she started the page after seeing the Australian version of it.
After four months, the page had 1.5 million members.
There wasn't an equivalent here yet, so she took it upon herself to set it up.
A team of moderators help run the page.
"[There's] no way I am doing it by myself.
"My team of moderators are all volunteers ... with experience moderating big pages."
The page was so busy that at any one time there could be up to 10 moderators working.
"I've been working behind the scenes because I can, my moderators have everything under control, I've been able to step away and focus on the next part of this which is setting up a website to provide more support for these small businesses.
"I want to continue to provide real value to this group ... to allow these businesses to not only survive during these times but come out thriving."
Businesses posting on the page said it was turning things around for them.
Andrew MacDonald, who started the company Absolute Wilderness - which makes freeze dried food packs for adventurers - with his father, said business had dried up when lockdown began.
"I joined (NZ Made) ... and it just went crazy.
"Basically, we have just been flooded with orders. It's going non-stop, my team have been absolutely busy at the factory."