Gary Rowett’s side needed a victory at the King Power Stadium to keep alive their slender hopes of avoiding relegation.
But the Foxes were denied by Oli McBurnie’s second-half equaliser, which condemned them to League One just 10 years after they were crowned English champions in a fairytale triumph.
Liam Millar put Hull ahead in the 18th minute before Leicester equalised through James Justin’s 52nd-minute penalty.
Luke Thomas put Leicester ahead two minutes later, but McBurnie extinguished their dreams of a great escape with his 63rd-minute leveller.
Second-bottom Leicester are seven points from safety with just two games left.
Leicester will play in the third tier for the first time since 2008-09 following an astonishing decline over the last five years.
It is a third relegation in four seasons for Leicester, who dropped out of the Premier League in 2023 and 2025.
After Jamie Vardy, Riyad Mahrez, N’Golo Kante and company defied 5,000-1 odds by winning the Premier League in 2016, Leicester reached the Champions League quarter-finals the next season and won the FA Cup in 2021.
But Leicester’s golden era is a distant memory as they face the unpalatable prospect of playing the likes of Bromley, Mansfield and Wycombe next season.
Crashing out of the Premier League in limp fashion three years ago should have been a wake-up call for Leicester’s Thai owner Aiyawatt Srivaddhanaprabha and much-maligned sporting director Jon Rudkin.
Turmoil on and off pitch
But Leicester’s hierarchy was painfully slow to address numerous flaws on the pitch, while the club’s ruinous finances have cost them a six-point deduction this season for breaching spending rules.
Vardy’s departure at the end of last season severed the last tie with the title-winning squad.
Marti Cifuentes, hired to lead a promotion push, struggled to rebuild an unbalanced and inexperienced squad before his sacking in January.
Interim boss Andy King was unable to turn the tide and relegation fears began to mount after Leicester blew a 3-0 half-time lead in a dismal 4-3 defeat against Southampton.
By the time Rowett was hired in February, the Foxes were two points from safety and the former Leicester defender has mustered only one win from his 12 matches since.
Boardroom blunders have been the defining influence on Leicester’s plummet towards League One.
Aiyawatt Srivaddhanaprabha has struggled to fill the shoes of his father, Vichai, who was killed in a helicopter crash at the King Power stadium in 2018.
Claudio Ranieri, architect of their title-winning campaign, was sacked just months after lifting the trophy, with Craig Shakespeare and then Claude Puel proving inadequate replacements.
Brendan Rodgers, who masterminded the club’s FA Cup triumph and two fifth-placed finishes in the Premier League, was dismissed as relegation beckoned in 2023.
Even when Enzo Maresca led Leicester to promotion in 2024, he immediately departed for Chelsea, necessitating the unpopular and unsuccessful appointment of Steve Cooper, who previously managed rivals Nottingham Forest.
Rudkin’s recruitment has been no better, with expensive flops Patson Daka, Oliver Skipp, Jannik Vestergaard and Harry Souttar adding to a wage bill that topped £200 million (US$270 million) in 2023 and reportedly contained no clauses to reduce salaries upon relegation.