It is the third consecutive year that the Warriors have kicked off their season at the Galway Sportsground, winning both matches in 2016 and 2017.
Hogg and Horne start at full-back and inside centre respectively, both having represented Scotland on this year's Summer Tour, with Hogg captaining his country for the first time against the USA.
On the bench Australia International Nick Frisby is in line to make his competitive Warriors debut.
Nikola Matawalu is also among the replacements having scored three tries in Glasgow's two pre-season fixtures.
Sam Johnson sustained a knee injury against Northampton Saints in the collision which led to him being replaced and he's expected to be out of action for six weeks, while Siua Halanukonuka injured his foot in pre-season training and is expected to be unavailable for eight weeks.
Glasgow Warriors Head Coach Dave Rennie, said: "The boys have worked hard and we're excited to rip into it in Round 1.
"We have a tough game away to Connacht who have been in really good form in pre-season so it's a big challenge first up.
"We've got a few guys coming back in which gives us a lot more experience and we think that will be important."
15 Stuart Hogg
Players unavailable due to injury: Brian Alainu'uese (back), Matt Fagerson (thigh), Siua Halanukonuka (foot), Sam Johnson (head/knee), Huw Jones (wrist), Lee Jones (achillies), Kiran McDonald (hand), Ali Price (groin) and Tim Swinson (lower limb)