The ex-Labour MP, who was born in Dewsbury, warned the hard left was “deluding a new generation with the same claptrap that it took my generation decades to discard” in an article for the Sunday Times.
Baroness Boothroyd, now an independent peer in the House of Lords, said the party was refighting 1980s ideological battles and risked “ending up on the scrapheap of history because of its own foolishness and self-inflicted wounds”.
She wrote: “My old party is galloping towards the precipice. I urge it to heed the jagged rocks before it is too late.”
Senior Labour heavyweights have already lined up to caution against electing Mr Corbyn - the frontrunner in the race to succeed Ed Miliband in September, including former prime ministers Tony Blair and Gordon Brown, as well as David Blunkett and David Miliband.
Baroness Boothroyd was the first and to date only female Speaker of the House of Commons, between 1992 and 2000.
In the Sunday Times, she blasted the decision to allow people to pay £3 to register as a voter in the Labour leadership election. She also criticised Ed Miliband’s resignation as party leader after May’s general election defeat as “an act of self-indulgence”.
She wrote: “What party in its right mind would allow a combination of far-left enemies, militant trade unions and first-time supporters to decide its fate?
“What enterprise would allow first-time customers a say in its future in return for a one-off donation of £3? The ancients were right. Those whom the gods wish to destroy, they first make mad.
“Now in the twilight of my public life, I watch with dismay as the clock is turned back. I can hardly believe that the battles we fought to save the Labour party are being fought all over again, this time against greater odds on more dangerous terrain.
“It may already be too late. The hard left is deluding a new generation with the same claptrap that it took my generation decades to discard.”