The Data Protection Commission has launched two separate statutory inquiries, into search firm Google and dating app Tinder.
Both inquiries relate to the handling of user data and are being opened under Europe's General Data Protection Regulations (GDPR).
The inquiry into Google will look at how the company processes location data, including information obtained through its Google Maps service.
There is also a concern around transparency, and whether users are made aware of how their data is handled by the company.
The DPC said it has launched the inquiry having received "a number of complaints from various consumer organisations across the EU".
The inquiry into MTCH Technology Services, the corporation behind Tinder, will also look at whether the company is transparent with users in how it handles data.
Meanwhile the commission will investigate whether the company is complying with rules around users' data requests.
This will specifically look at whether the firm gives users all of the information it holds on them when requested, and whether it is deleting all of that data when asked to do so.
The DPC said this inquiry has come about after concerns were raised "by individuals both in Ireland and across the EU".
Companies found to be in breach of GDPR can be fined up to €20m or 4% of global turnover - whichever is higher.
Firms can also be forced to comply with any of the regulations that they are found to be in breach of.
It is not clear when the investigations will be completed, however there is not expected to be any outcome until the latter part of this year.