EZ Importer ‑ Order Importer

It's not cheap, even after special pricing for volume, but it's a solid app that does exactly what it advertises.

After a few days of cleaning and arranging our data and a couple of quick fixes helped by the solid support, we had no trouble importing ~90k orders into Shopify in about 36 hours.

One suggestion: let us input default values for fields directly from mapping, so we don't have to add for example a long column with the same country code in every cell. But still 5* and highly recommended for big order imports.