Injuries have forced Townsend into selecting a new second row with Max Williamson and Grant Gilchrist replacing Gregor Brown and Scott Cummings, both sidelined following last week's extraordinary 50-40 win over France at Murrayfield.
Zander Fagerson starts at tighthead prop, having been a replacement against France - a match where Scotland scored seven tries, with D'arcy Rae moving to the bench.
Otherwise the rest of the pack is unchanged, with Scotland retaining the same back division that featured against France.
Player of the match Kyle Steyn, who scored two tries against the French, is on one wing with Darcy Graham, who also grabbed a double at Murrayfield last weekend to top Scotland's list of all-time try-scorers with 37, on the other.
Blair Kinghorn is again at full-back, with captain Sione Tuipulotu and Huw Jones forming the centre partnership for the fifth straight championship match.
Scrum-half Ben White is named alongside inspirational stand-off Finn Russell.
Among the replacements, the likes of lock Alex Craig, back row Magnus Bradbury and Kyle Rowe, who will cover the back-three positions, feature for the first time in this Six Nations.
Scotland could be crowned champions for the first time in the Six Nations era if they beat Ireland and France slip-up at home to England in the last of three games on March 14th.
Scotland (15-1)
Blair Kinghorn; Darcy Graham, Huw Jones, Sione Tuipulotu (capt), Kyle Steyn; Finn Russell, Ben White; Jack Dempsey, Rory Darge, Matt Fagerson; Grant Gilchrist, Max Williamson; Zander Fagerson, George Turner, Pierre Schoeman
Replacements: Ewan Ashman, Rory Sutherland, D'arcy Rae, Alex Craig, Magnus Bradbury, George Horne, Kyle Rowe, Tom Jordan
Coach: Gregor Townsend (SCO)