The Government is to approve plans to make it illegal for anyone younger than 18 to get married.
The Seanad is to vote in favour of a motion to stop anyone under the age of 18 being able to marry in a bid to clamp down on forced marriages.
It is currently possible to get married at age 16 or 17, provided a court has given its permission.
Independent senator Jillian van Turnhout said Ireland needed to act as a world leader in stopping arranged marriages.
"Ireland needs to stand up internationally and say we've set the marriage age at 18 and that this is something worldwide that we need to look at," she said. "This motion is about protecting childhood."