Joshua Giurgi scored the only goal of the game, in the third-minute, as Colin O'Brien's side continue their preparations for this May's UEFA Under-17 European Championships.
Giurgi cut in from the left wing, before his right-footed shot curled into the bottom-right corner, beating Mikolaj Bieganski.
Speaking after the game, Under-17 Head Coach Colin O'Brien was happy to get the win against quality opposition.
"Overall, it was a good performance. We still need to tidy up in certain areas, and the players know that. We were really good defensively. There was a lot of good things today, but there's plenty to work on."
With only three more matches, before this year's European Championships, O'Brien knows time is tight, to work with his players, but was happy with what he saw against the Polish.
"We're still educating players about tournament football, and now look forward to the game later this week."
O'Brien's side return to action on Friday, with an International Friendly against Belgium, in Marbella.
Poland: Mikolaj Bieganski, Nikodem Niski, Lukasz Bejger, Filip Dymerski, Jakub Kaminski (Daniel Szelagowski 74), Kacper Kozlowski, Hubert Turski, Michal Rakoczy (capt), Bartosz Zynek (Jan Bieganski 65), Daniel Dudzinski (Mateusz Stepien 65), Jakub Niewiadomski
Republic of Ireland: Gavin Bazunu; James Furlong, Anselmo Garcia MacNulty, Timi Sobowale (Andrew Omobamidele 61), Sean McEvoy; Seamas Keogh (capt), Joe Hodge, Ronan McKinley (Roland Idowu 61); Joshua Giurgi, Sean Kennedy (Brandon Holt 55), Conor Carty
Referee: Guillermo Paradas Mazuela (ESP)