Almost 300 new jobs have been created in Dublin and Kerry at a health provider and a financial services firm.
Spectrum Wellness unveiled a 4 million euro investment at its Dublin base creating more than 100 new jobs.
The new roles will be in account management, marketing, operations, product development and mental health case management.
Spectrum Wellness creates and builds personalised programmes for corporate clients and their employees.
The 100 new jobs will treble the size of the workforce.
Its 27-year-old co-founder, Stephen Costello, said the jobs have been created because of significant business growth in Ireland.
"Turnover is forecast to hit 4 million euro this year, with secured contracts bringing that to 7 million euro by the end of 2019," he said.
"The investment in jobs is a clear signal about the confidence we have in the future of the company, not only in Ireland but in markets such as the UK, Europe and the US.
"Our aim is to grow Spectrum Wellness to be a leading global player in corporate health and wellness, and we are currently looking at a range of funding options that will support our international growth.
"This might sound ambitious but, according to the Global Wellness Institute, 43 billion dollars is being spent globally each year on health and wellbeing workplace programmes, covering only 9% of workforces.
"The global market opportunities in this area are therefore enormous, so I believe that our goal is wholly achievable."
Spectrum Wellness supports 175,000 employees across 1,000 companies in Ireland.
Minister for Business, Enterprise and Innovation, Heather Humphreys, welcomed the announcement.
She said: "Not only is the company proposing to create a significant number of new jobs, but it is also helping businesses to support their staff with a wide range of services that will have a positive effect on overall health, physical and mental.
"As an Enterprise Ireland client, it's fantastic to see this young company doing so well."
Kerry-based fintech firm Fexco also revealed an expansion at its headquarters in Killorglin, creating 175 jobs over three years.
Fexco has developed payments and foreign exchange products and solutions including Dynamic Currency Conversion (DCC), Multi Currency Pricing (MCP), Tax Free Shopping and Retail FX.
The new high-skilled roles includes ICT engineering, software and sales.
Chief executive Denis McCarthy said: "Our plans to hire an additional 175 people for our Irish operations, based primarily in Killorglin, demonstrates Fexco's commitment to this region, one synonymous with entrepreneurship, innovation and success in the ICT and fintech sectors."
Recruitment for the roles at Fexco has started.