At home against Irish sides their record is won three, lost two. Leinster's only defeat in their past seven encounters was 13-34 against the Dragons at Rodney Parade two weeks ago.
The Dubliners have won on both their previous visits to St Helens, playing against Swansea RFC, 34-18 in the Celtic League in September 2001 and 51-10 in the European Cup in October 2002.
The teams met on three occasions last season (the first in the 1st round of the Celtic Cup) with Leinster coming out on top with two wins and a draw.
"We made some good signings in the summer and are a team full of confidence," said Ospreys captain Barry Williams. "The visit of Leinster presents a huge challenge, but preparations have been going well. It is a match we are looking forward to before the Heineken Cup swings into action next week."
'Leinster will provide a real test of how far we have developed as a squad,' added Ospreys manager Derwyn Jones. 'Leinster have now had three weeks together since their internationals returned and they will give us a true test of where we are in preparing for the Heineken Cup.
'They have a talisman up front in Reggie Corrigan, great presence in the second row from Malcolm O'Kelly and in Brian O'Driscoll they have one of the few world-class players in the British Isles," he told BBC Wales Sport.
Stefan Terblanche has a broken bone in his left foot and is hoping to be available for selection against Edinburgh on 12 November, while Shaun Connor is recovering from a fractured fibular but should be back a week earlier.
Ospreys (from): A Durston, R Mustoe, S Parker, D Bishop, E Seveali'i, S Williams, G Henson, M Jones, A Williams, J Spice, D Jones, A Jones, A Millward, P James, M Davies, B Williams (capt), A Newman, L Bateman, B Cockbain, R Jones, A Lloyd, R Pugh, J Bater
Leinster: G Dempsey; G Brown, B O'Driscoll, F Contepomi, D Hickie; D Holwell, G Easterby; R Corrigan (capt), S Byrne, R Nebbett, M O'Kelly, B Gissing, A McCullen, S Jennings, D Dillon
Replacements: E Byrne, G Hickie, L Cullen, E Miller / C Potts, B O'Meara, G D'Arcy, S Horgan
Referee: David Changleng (Scotland)