As well as stints playing for Leinster and Munster, the Dublin-born 27-year-old has starred at AIB League level for UCD and Garryowen and his list of Ireland honours includes Schools, Under-21 and 'A' caps.
Wasps director of rugby Tony Hanks said: "Eoghan gives us depth at out-half which is important in the Guinness Premiership and will add competition for Danny (Cipriani) and Dave (Walder) at 10.
"He brings a strong kicking game to the team and he has a wealth of experience having played with Ireland 'A' as well as plenty of rugby at Premiership level.
"He is a quality out-half but he also has the ability to play full-back which, along with his strong kicking game, is something that could be really valuable to us this year - especially with the importance that kicking is playing in the modern game."
Hickey's most recent provincial experience saw him play 10 times for Munster in the 2006/07 Magners League, kicking 30 points.
He also boasts Heineken Cup caps for Leinster and London Irish, while a loan spell with Worcester Warriors last season saw him make his European Challenge Cup debut.