O'Kelly, Ireland's most-capped international, will line up alongside Trevor Hogan in the second row with Shane Jennings returning from injury to form an exciting back row alongside Stephen Keogh and January's Bank of Ireland Leinster Player of the Month Keith Gleeson.
Brian Blaney starts at hooker and will be flanked on either side of the front row by Stan Wright and former Springbok Ollie Le Roux, who donned the number 2 jersey last time out in Leinster's 24-17 victory over Cardiff Blues.
In the back-line, Chris Whitaker will captain the side from number 9 and he will be partnered at half-back by Felipe Contepomi, while Luke Fitzgerald starts again at full-back after scoring in Leinster's last outing.
Another try scorer that day, Michael Berne starts at outside centre alongside Christian Warner with both the left and right wingers set to be announced closer to kick-off. The outside back replacement will also be confirmed then. The fit-again Shane Horgan is one of the players in the running for the wide berths.
LEINSTER (v Connacht): Luke Fitzgerald; Shane Horgan/Gary Brown/Fionn Carr/Felix Jones (three to be omitted), Michael Berne, Christian Warner, Shane Horgan/Gary Brown/Fionn Carr/Felix Jones (three to be omitted); Felipe Contepomi, Chris Whitaker (capt); Ollie Le Roux, Brian Blaney, Stan Wright, Trevor Hogan, Malcolm O'Kelly, Shane Jennings, Keith Gleeson, Stephen Keogh.
Replacements: Cian Healy, Stephen Knoop, Cameron Jowitt, Kevin McLaughlin, Chris Keane, Eoin O'Malley, AN Other.