It is the first time membership of a Victorian club has hit 50,000, and Cook said that was largely due to the determination of members.
"The members have driven us to that number. There is a lot of pride out there amongst the members to be the first Victorian club to reach 50,000," he said.
Of the figure, about 11,400 are for restricted category members.
Cook said the Hawks' membership tally would be the envy of most clubs and was keen to dismiss suggestions that figures had been fudged.
"There are no cats, dogs, budgies and whatever else [Collingwood president] Eddie [McGuire] wants to put in there. That's just envy that we've achieved it."
But Cook stopped short of suggesting that Hawthorn was now a serious competitor with Collingwood as one of the AFL's powerhouse clubs.
"We don't make comparisons in those terms. I'm not sure what Collingwood's membership breakdown is. They're doing well, I know that."
Cook said Hawthorn's 2008 premiership, growth in Tasmania and a desire to have a reserved seat at MCG home games were reasons behind the Hawks' success.
"Tasmania is a terrific story. The Tasmanian community has really embraced Hawthorn and we've got close to 7000 members down there, with the aim of having 10,000 in the next few years," he said.
"The only memberships we have that are not in these figures are a one-game membership for Tasmania and a no-access member, which is an MCC member who has already got a membership but wants to show their flag as a Hawthorn supporter. There are only 160 of those."
MCG reserved seat holders have increased from 11,000 last year to 19,000, while 30 per cent of total club memberships are for non-Victorian members.
