Glasgow's Pat MacArthur, Tim Swinson, Alex Dunbar, Peter Horne, Peter Murchie and Tommy Seymour, Saracens' Duncan Taylor and Steven Lawrie and Greig Tonks of Edinburgh, have all been named in the squad for the first time.
The squad will have a three-day training camp in Perthshire at the end of the month before flying out to South Africa on May 31.
There they will play Samoa in Durban on 8 June and South Africa in Nelspruit on the 15th before wrapping up their tour against Italy on June 22.
Johnson, who is currently acting as interim coach but was also appointed Scotland director of rugby last week, is pleased with his selection.
"First up, it's a strong squad designed to win Test matches against quality opposition," said the Australian, who will give up his coaching position as soon as a permanent replacement is found.
"We've continued to monitor the players' form closely and we've been pleased that Glasgow have reached the knockout stages of the PRO12.
"We are taking the opportunity to have a look at some players and want to assess what they're like at this level. We need to be able to find out whether players who've done the business for their clubs can replicate that form in international footy."
Scotland - Backs: A Dunbar (Glasgow), T Heathcote (Bath), P Horne, R Jackson (both Glasgow), G Laidlaw (Edinburgh), S Lamont, P Murchie, H Pyrgos (all Glasgow), M Scott (Edinburgh), T Seymour (Glasgow), D Taylor (Saracens), G Tonk, T Visser (both Edinburgh).
Forwards: J Barclay (Glasgow), J Beattie (Montpellier), K Brown (Saracens, capt), G Cross, D Denton (both Edinburgh), A Dickinson (Sale), R Ford, G Gilchrist (both Edinburgh), R Grant (Glasgow), J Hamilton (Gloucester), A Kellock (Glasgow), S Lawrie (Edinburgh), M Low, P MacArthur (both Glasgow), E Murray (Worcester), A Strokosch (Perpignan), T Swinson, R Wilson (both Glasgow).