The Swiss fourth seed was largely untroubled by Rosol as he secured a straightforward 6-2 6-3 7-6 (7-3) victory on Rod Laver Arena on Saturday.
Wawrinka, the 2014 champion in Melbourne, is yet to drop a set on his way to the fourth round, where Raonic awaits.
The two-time grand slam winner extended his run of victories to seven matches, having won the title in Chennai in the lead-up to the Australian Open.
Wawrinka's tally of winners has exceeded his unforced errors in every match at the year's first grand slam so far and that continued against Rosol.
The Czech was no match early on for Wawrinka, who did cough up a break in the second set before steadying.
Rosol managed to stay with Wawrinka during the third, but the latter pulled away with five straight points to finish the tie-break.
Wawrinka  bt Rosol 6-2 6-3 7-6 (7-3)
Wawrinka - 18
Rosol - 2
Wawrinka - 45/23
Rosol - 24/33
BREAK POINTS WON
Wawrinka - 4/10
Rosol - 1/3
FIRST SERVE PERCENTAGE
Wawrinka - 58
Rosol - 54
PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE
Wawrinka - 80/59
Rosol - 69/45
Wawrinka - 106
Rosol - 83