The Bulls face going into extinction if they do not pay a £78,000 tax bill to HMRC on Monday.
Iranian jokester Djalili will play two sell-out gigs at the Courtyard Theatre, which is situated down the round from Hereford's Edgar Street ground, with all the proceeds going to the club's cause.
Djalili is a Chelsea fan, but remembers fondly Ronnie Radford's wonder goal that helped knock Newcastle United out of the FA Cup in 1972 and says it would be "such a blow" if they were lost from football.
"They could cease to exist and if Hereford United go it would be such a blow," Djalili told reporters. "Grassroots football is really struggling right now but it's such an important part of British culture, I worry that if Hereford go then other clubs could follow.
"A passion of mine is football, especially grassroots football. Every football fan has Hereford in their minds because of Ronnie Radford's fantastic equaliser. My production manager told me that Hereford were going to be wound up and I couldn't believe it. I sent a supportive tweet out and it's gone from there.
"They are relying on this. If Hereford don't reach their target they will cease to exist by the end of Monday. There's a bit of pressure – let's hope I'm funny."
Radford is expected to be in the crowd for one of Djalili's shows, which he is doing free of charge.
Hereford, who were last in the Football :eague in the 2011-2012 season, are facing possible relegation from the Conference this campaign as they sit only one place above the bottom four.