"Mark Anscombe pulled me to one side on Monday and said that I was going to captain the team - I was delighted," said the Ireland second row.
"For me, I am just going to concentrate on my own game, get the lads behind me and hopefully we can put in a decent performance tomorrow night."
Tuohy's inclusion is one of 12 changes that Anscombe has made to the side that played Leinster at Ravenhill last weekend.
There is a completely new back-line, with Craig Gilroy starting at full-back, David McIlwaine selected on the right wing and Michael Allen and Hughes Insurance Academy Player of the Year Stuart McCloskey starting in the centre.
Rory Scholes is named on the left wing, with James McKinney starting at out-half and Michael Heaney picked at scrum half.
Up front, Callum Black starts at loosehead prop with hooker Rob Herring and Andrew Warwick keeping their places in the front row.
Lewis Stevenson partners Tuohy in the second row, while Mike McComish and Sean Doyle start either side of number 8 Nick Williams in the back row.
Bronson Ross has recovered from neck surgery and is selected on the bench along with fellow forwards Kyle McCall, Adam Macklin, Neil McComb and Conor Joyce. Backs David Shanahan, Ricky Andrew and Peter Nelson complete the matchday squad.
With the hard-earned bonus point secured against Leinster, Ulster are guaranteed to finish in fourth position in the league and will be involved in the play-offs next week.
Who Ulster will play in that match will be determined by results elsewhere. Full details of ticket arrangements for the semi-final will be released following the completion of the final round of PRO12 games.
ULSTER (v Munster): Craig Gilroy; David McIlwaine, Michael Allen, Stuart McCloskey, Rory Scholes; James McKinney, Michael Heaney; Callum Black, Rob Herring, Andrew Warwick, Lewis Stevenson, Dan Tuohy (capt), Mike McComish, Sean Doyle, Nick Williams.
Replacements: Kyle McCall, Bronson Ross, Adam Macklin, Neil McComb, Conor Joyce, David Shanahan, Ricky Andrew, Peter Nelson.