O'Donoghue and Schifcofske will arrive at Ravenhill in July
Ulster have signed Queensland Reds players Clinton Schifcofske and Ed O'Donoghue on two-year deals.
Schifcofske, a 32-year-old full-back and wing, is a former rugby league star who has played for Australia A.
O'Donoghue is a 25-year-old former Northampton and Worcester lock and comes in as the replacement for the departing Justin Harrison.
The Irish-qualified O'Donoghue was raised in Brisbane and was in the Australia U19 squad.
"It will be great to develop my skills under the experienced Ulster management" said O'Donoghue.
Schifcofske crossed codes at the end of 2006 after a 10-year career in rugby league.
In his first match for Australia A, the hard running full-back scored a personal tally of 23 points and has a kicking success rate of almost 80 per cent.
"I'm really looking forward to this new and exciting chapter in my life and rugby career," he said.
"I know the Ulster fans are very passionate and supportive of their team and I'm really looking forward to myself and the team giving them plenty to cheer about.
Clinton is a hugely respected figure in Australian rugby union and rugby league
"I was also delighted to be coming over with my current team-mate here at the Reds, Ed O'Donoghue.
"Ed's become a good friend of mine and is a terrific young player with loads of potential."
The pair are the first overseas signings by new coach Matt Williams with another two expected to to be signed in the coming weeks.
Ulster are facing a summer exodus with Harrison, Tommy Bowe, David Humpreys, Neil Best, Roger Wilson, Mark Bartholomeusz and Kieran Campbell ending their time at Ravenhill.
"Clinton is a hugely respected figure in Australian rugby union and rugby league," said Williams.
"He's an experienced captain and leader, essential qualities with our young back line. Clinton is also a very high percentage goal kicker and a confident Super 14 player.
"Ed is a rare find - an experienced European player currently playing Super 14 and Irish qualified. He is great replacement for Justin Harrison."