Demonstrators from the Yorkshire Moorland Communities say their livelihoods and whole communities are under threat by what they call "misleading statements and actions" by the BBC presenter.
Mr Packham, who was giving a talk at the Royal Hall aimed at getting more families involved in wildlife projects, previously called for a grouse shooting ban after a hen harrier was killed by a "savage" trap a Scottish grouse moor.
Members of the Yorkshire Moorland Communities say their livelihood depends on moorland activity including grouse shooting.
The BBC presenter was met by more than 100 protesters, many of whom held placards reading "Chris Packham – ignoring science since 04.05.1961!” (Packham’s date of birth), and a large banner declared: “Moorlands are our lives, our livelihood and our community. We stand in unity to protect them."
Roy Burrows, an estate manager at a nearby moorland, said: "Chris Packham and his followers are wilfully misrepresenting facts and distorting clear scientific evidence.
Mr Packham has frequently posted about his dislike for grouse shooting on social media. He also spoke at last month's Green Party conference about his campaign to ban driven grouse shooting.
Protesters sang chants on Saturday evening including: "From bus drivers to gamekeepers, together we thrive, we need to protect, moorland community lives”.
They were supported on Twitter by Ian Botham who said: “Are you seeing the passion and love of the countryside from the people who look after it....Mr Packham ??”
"This is reinforced by clear scientific evidence, which is too often wilfully ignored by our opponents.
"The facts are very clear: without grouse shooting these areas would lose millions of pounds in investment each year causing lives and livelihoods would be destroyed, alongside one of Britain’s most unique habitats.
"It is disgraceful that a rich celebrity from Hampshire thinks it is okay to dictate to the hard-working people of Yorkshire how we should live our lives. Moorland and other rural communities seem to be the only cultural minority Chris Packham and others think it is okay to abuse. Enough is enough.”