Hollerbach lasted less than two months in the job after he was appointed to succeed Markus Gisdol on 23 January (AEDT).
Although his tenure started in relatively positive fashion with a 1-1 draw at RB Leipzig, Hollerbach ultimately never managed to guide Hamburg to a win.
His spell ended in crushing fashion, as Hamburg was thumped 6-0 by Bayern Munich at the Allianz Arena.
Hollerbach leaves Hamburg embroiled in a relegation battle, sitting second from bottom and seven points adrift of safety.
Titz makes the step up from the club's second string and will be the man charged with ensuring Hamburg does not suffer relegation from the Bundesliga from the first time in its history.
He will be assisted by Thomas von Heesen, who has been brought in on a temporary deal to act as an "advisor" to oversee "sporting activities" after the sacking of Jens Todt on Friday (AEDT).
Chairman Frank Wettstein explained that the 6-0 demolition at Bayern was ultimately the final straw for Hollerbach.
"We analysed and discussed the 6-0 defeat on Saturday at length," Wettstein told the club's official website. "We concluded, in light of our situation fighting against relegation, that we had to act.
"I have extended the thanks of myself and the club to Bernd Hollerbach. We have also arranged to meet personally. We did not react immediately in the aftermath of Saturday's game, but we instead took our time.
"Christian Titz will give the team a new impulse, put the players to the test and approach things with a fresh perspective. We are very confident of putting in a different performance against Hertha [Berlin].
"It's clear that we need to muster all of our strength. Bernhard Peters [sporting director] and I are in good contact with Thomas von Heesen and we're excited that he will be on board for the next eight matches."