Clear Day Nurseries is investing £1m to build a new nursery in Lisburn, creating 30 jobs.
The company is also set to carry out a £250,000 refurbishment of its Little Gems Day Nursery in Dundonald.
Employing over 170 staff, the company already has six nurseries under the Clear Day branding.
The new Lisburn facility will be based at the old Point Bar & Grill site on Bridge Street, with places for up to 100 children.
The announcement comes as Clear Day was voted one of the Top 20 nursery groups in the UK.
Audrey McCracken, Operations Manager at Clear Day Nurseries, said the new nursery is due to open in early 2019.