The O2 is paying for 23 Gardai to police tonight's Hardwell gig.
The venue says it's standard practice that, at larger events, the state supplies a certain number of officers, and the promoters hire in the rest.
The O2 says a full medical and security team will be in place, and that anyone under 18 or anyone who appears intoxicated won't be allowed in.
The precaution comes after more than 100 young people fell ill at the Dutch DJs gig in Belfast last night.
Tests are being carried out to see if drink or drugs were to blame.
Fionnuala Sheehan from DrinkAware.ie is encouraging people going to the gig to act responsibly.
