Quigg boxes at Featherweight for the second time having landed the WBA International title in his first fight at his new weight in December in Manchester with a ninth round stoppage.
London represents another first for Quigg as the one-time world title holder has future hall of fame trainer Freddie Roach in his corner for the first time as he takes on Simion. The WBA have sanctioned the fight as an eliminator.
At lightweight, Luke Campbell MBE will take on Darleys Perez, also in an eliminator for the number one position with the WBA.
Campbell defended his WBC Silver title for the second time in February with a second round demolition of Jairo Lopez in his hometown of Hull, following hot on the heels of his impressive stoppage win over Derry Mathews in October in Liverpool.
Olympians Lawrence Okolie, Joe Cordina and Josh Kelly are all given places to shine on the massive card.
The trio represented Team GB in Rio last summer before turning to the paid ranks, with Okolie the first to make his debut and in spectacular fashion in Manchester earlier this month.
Okolie has been pitted against Russ Henshaw, whilst Kelly fights Faheem Khan after making is pro bow in Glasgow on the undercard of Ricky Burns’ World Super-Lightweight title unification battle with Julius Indongo earlier this month.
Cordina claimed the number one slot in a draw between the three former amateur stars this week and will open the show opposite Sergej Vib
The seventh bout to be confirmed is Katie Taylor. The Olympic gold medallist, who has raced to 4-0 already this year, battles Nina Meinke in a WBA title eliminator as Eddie Hearn pushes for a fast-tracked championship victory.
Full card as it stands:
Anthony Joshua v Wladimir Klitschko (WBA/IBF/IBO heavyweight titles)
Scott Quigg v Viorel Simion (Featherweight)
Luke Campbell v Darleys Perez (WBA lightweight title eliminator)
Katie Taylor v Nina Meinke (WBA Lightweight title eliminator) **
Lawrence Okolie v Russ Henshaw (Cruiserweight)
Joe Cordina v Sergej Vib (Super-featherweight)
Josh Kelly v Faheem Khan (Welterweight)
LIVE ON SKY SPORTS BOX OFFICE 6.25pm
JOE CORDINA VS SERGEJ VIB
4 x 3 mins Super-Featherweight Contest
KATIE TAYLOR VS NINA MEINKE
10 x 2 mins WBA Inter-Continental Lightweight Championship
LUKE CAMPBELL VS DARLEYS PEREZ
12 x 3 mins WBA World Lightweight Championship Eliminator
SCOTT QUIGG VS VIOREL SIMION
12 x 3 mins IBF World Featherweight Championship Eliminator
ANTHONY JOSHUA VS WLADIMIR KLITSCHKO
12 x 3 mins Heavyweight World Championship
LAWRENCE OKOLIE VS RUSSELL HENSHAW
4 x 3 mins Cruiserweight Contest
Joshua v Klitschko will be live on Sky Sports Box Office in the UK with coverage beginning at 6pm. Joshua backers
Joshua backers Showtime pick up live coverage in the US, whilst HBO will show the bout delayed in the evening (US time).
RTL have exclusivity on Klitschko in his preferred home of Germany with coverage from 7pm CET.
Ring Walk times:
Joshua and Klitschko will begin ring walks at 9.35pm and be in the ring by 9.50pm for a 10pm first bell.
(1.35pm to 2pm PT / 4.35pm to 5pm ET in the US / 10.35pm to 11pm CET).