Police armed with a search warrant raided his home in Marlowe Crescent, Garforth, on September 23 last year while he was on holiday abroad with his family.
Computer equipment was seized including a desktop computer, hard drives and USB memory sticks.
Police discovered a total of 36,003 rape images and videos of children including 5,488 at category A – the most serious level.
Taggart served as Leeds Labour lord mayor, a Labour city councillor and chairman of West Yorkshire Police Authority.
Detective Superintendent Pat Twiggs, who led the West Yorkshire Police investigation, said after sentencing: “The crimes he pleaded guilty to represent a high volume of images – many of the most serious kind – and cover a significant period of time.”
The court heard that images featured children being sexually abused by adults – including children under five being violently raped.
Police also found 30 extreme images depicting sexual activity with animals.
Taggart, of Marlowe Court, Garforth, pleaded guilty to the offences.
Judge Mairs told Taggart: “I accept that both your personal and public reputation, that at one time stood high in the city, now effectively lies in the gutter.”