Harley, who has been sidelined with a thumb injury for the last six weeks, returns to the Warriors starting line-up this weekend, along with Ryan Wilson who captains the side.
Josh Strauss is also set to return having missed the last four weeks with concussion, with the Scotland international backrower named amongst the replacements.
The Warriors return to GUINNESS PRO12 action, following their 22-5 win over Racing 92 in the European Rugby Champions Cup at Rugby Park last Saturday.
Peter Murchie, who replaces Stuart Hogg at full-back, makes his first start since September and first appearance since early January after recovering from an elbow injury.
Lee Jones replaces Taqele Naiyaravoro on the right wing, with the Australian international switching to outside centre, where he finished the game against Racing 92.
Rory Hughes starts on the left wing, following a successful loan spell at London Scottish where he scored five tries in four appearances.
Sam Johnson continues at inside centre and will combine with Naiyaravoro in midfield.
Duncan Weir makes his 101st appearance for the club at fly-half and Grayson Hart comes in for Ali Price at scrum-half.
In the pack Ryan Grant returns at loosehead, hooker Pat MacArthur comes in for Shalva Mamukashvili and Sila Puafisi continues at tight-head.
Leone Nakarawa moves back into the second-row from Number 8 and combines with USA international Greg Peterson.
It’s an all new back-row with Harley returning at blind-side in place of James Eddie, Chris Fusaro replaces Simone Favaro at open-side and captain Ryan Wilson is named at Number 8.
Gordon Reid, D’arcy Rae, Gregor Hunter and Glenn Bryce have also been added to the matchday squad this weekend and could feature from the bench.
Glasgow Warriors head coach Gregor Townsend said: "We're going up against an Ospreys side who are a point above us in the league and have won five out of their last six games in the PRO12, so we're well aware of the challenge we face on Sunday.
"We're delighted to welcome Rob (Harley) and Josh (Strauss) back into the squad after missing our last few games because of injury.
"What has been pleasing over the past few weeks has been the determination of a number of players to seize their playing opportunities.
"A few of our squad this weekend have been waiting for a while to get their opportunity and we're looking forward to them being positive and committed in their play."
Glasgow Warriors team to play Ospreys, GUINNESS PRO12, Liberty Stadium, Sunday 31 January (kick-off 2.30pm) – live on BBC ALBA:
15. Peter Murchie
14. Lee Jones
13. Taqele Naiyaravoro
12. Sam Johnson
11. Rory Hughes
10. Duncan Weir
9. Grayson Hart
1. Ryan Grant
2. Pat MacArthur
3. Sila Puafisi
4. Greg Peterson
5. Leone Nakarawa
6. Rob Harley
7. Chris Fusaro
8. Ryan Wilson (C)
16. James Malcolm
17. Gordon Reid
18. D’arcy Rae
19. Josh Strauss
20. James Eddie
21. Ali Price
22. Gregor Hunter
23. Glenn Bryce
Not available due to injury: Adam Ashe (shoulder), Mike Blair (concussion), Fraser Brown (ankle), Kevin Bryce (shoulder), Mike Cusack (chest), Alex Dunbar (posterior thigh), Simone Favaro (ribs), Tyrone Holmes (foot), Henry Pyrgos (wrist), Fergus Scott (shoulder) and Richie Vernon (shoulder).