Wicketkeeper O'Brien (calf) and bowler Young (elbow) missed the recent series against Afghanistan along with paceman Boyd Rankin, who was unavailable.
All three are back in the squad for the Malahide contests.
"I'm certain there will be two tough games when we meet Pakistan," said Ireland head coach John Bracewell.
Ireland famously beat Pakistan in the 2007 World Cup thanks primarily to Niall O'Brien's 72 while William Porterfield's century in Adelaide was not enough to give Ireland a quarter-final slot when the sides met in the 2015 event.
The most recent meetings on Irish soil came in 2013 when a Paul Stirling century and a whirlwind unbeaten 84 from just 47 balls from Kevin O'Brien saw Ireland earn a dramatic last ball tie in the first ODI.
Pakistan won the second by two wickets despite Ed Joyce scoring an unbeaten 116.
"It's great to have an almost full strength squad to choose from," added Bracewell.
"The bowling unit performed superbly against Afghanistan with the younger seamers in particular putting their hands up.
The return of Boyd and Craig adds to that department and gives us plenty of options which is exactly what a coach wants.
"The return of Niall adds experience to the top order. We tried a few different permutations with the batting order last week - some of which worked and some which didn't.
"Ed Joyce was obviously the stand-out performer in his new role as opener, and it was great to see Gary Wilson return to form.
"It should be a fantastic series - there's a great recent history between the two countries with some great matches over the past decade."
Ireland squad:
William Porterfield (Warwickshire, capt), John Anderson (Merrion/Leinster Lightning), Peter Chase (Malahide/Leinster Lightning),  Ed Joyce (Sussex), Tim Murtagh (Middlesex), Andy McBrine (Donemana/NW Warriors), Barry McCarthy (Durham), Kevin O'Brien (Leicestershire/Leinster Lightning), Niall O'Brien (Leicestershire, wk), Stuart Poynter (Durham), Boyd Rankin (Warwickshire), Paul Stirling (Middlesex), Gary Wilson (Surrey, wk), Craig Young (Bready/NW Warriors).
Fixtures
18 August: Ireland v Pakistan, Malahide   (10:45 BST)
20 August: Ireland v Pakistan, Malahide  (10:45 BST)
Ireland are boosted by the return from injury of Niall O'Brien and Craig Young for the two-game one-day international series against Pakistan next month.