The pair are expected to compete to become Leeds United's number one this coming season.
Blackman will spend the coming campaign on loan at Elland Road from Chelsea, and is expected to compete with Peacock-Farrell to be Leeds' number one goalkeeper.
Peacock-Farrell ousted Felix Wiedwald and Andy Lonergan towards the end of last season, prompting the pair's departures earlier in the window.
But Leeds' decision to strengthen in the Ulsterman's position can only be a good thing, according to the player himself.
"All Championship clubs always need at least two first choice goalkeepers now, that's how it is I think," Peacock-Farrell told LUTV. "(Jamal is) coming here to play games, but I'm here as well and I want to be playing games. So the competition's going to be there and it'll be a nice, healthy competition for the whole season."
Blackman is certainly the more experienced of the two, impressing for Sheffield United last season after temporary spells at Ostersunds FK and Wycombe Wanderers.
However, Peacock-Farrell has had the past few weeks to catch the eye of new Leeds boss Marcelo Bielsa, which could work in his favour.
Below first team level, the Whites can also call upon Kamil Miazek, Will Huffer and Harrison Male between the sticks.
Who should be Leeds' number one this season?