Tenants at two notoriously dilapidated Upper East Side developments slapped the city’s scandal-rocked Housing Authority with lawsuits on Friday demanding better living conditions.

Residents of the Stanley M. Isaacs Houses and Holmes Towers claim in legal papers filed in Manhattan Housing court that the New York City Housing Authority is miserably failing to provide legally required safe and decent housing.

The suits demand NYCHA take immediate action to fix rat infestations, broken elevators, busted heat and hot water systems and other issues that confront the roughly 1,100 families who call the neighboring developments near First Avenue home.

The Post reported last year that both housing projects and nearby Robbins Plaza, a 150-unit building for seniors, scored the worst maintenance grades in the NYCHA system and are ranked among the most troubled public housing complexes in America.

“We are living as if it’s a third world country,” said Saundrea Coleman, a co-founder of the Holmes-Isaacs Coalition, during a rally outside the Centre Street courthouse. “It is time to fight back. Any other landlord in this city would have been legally held accountable.”

Coleman was one of roughly two dozen tenants who showed up to personally drop off the suits, and then march about a half-mile to NYCHA’s Broadway headquarters to hand-deliver copies there.

“This … lawsuit is not just for us, it is for every NYCHA stakeholder that has gone without timely repairs and is living in hazardous conditions due to the decades of neglect from the largest landlord in New York City,” she added.

The authority estimated two years ago that both complexes needed a combined $100 million in immediate repairs.

Joanna Davis, 45, said during the rally that her seventh-floor apartment at Holmes Towers is “horrible” and saturated with gaping “holes everywhere.”

“There’s roaches everywhere,” she added. “Every day I spray Raid, and I’m like a very clean person, but the hallways are insane. [NYCHA] could care less”

Four years ago, NYCHA hoped to fund at least $25 million in repairs by leasing land currently used as a playground to a developer to build an apartment tower with affordable and market-rate units.

However, the authority pulled those plans earlier this year following staunch community opposition.

The de Blasio administration announced plans to expand development on NYCHA parking lots and other little-used lands in December 2018 as a way to raise desperately needed cash for repairs, but observers say those plans seem to have stalled too.

Rep. Carolyn Maloney (D-NY), who joined the tenants, said: “it is unacceptable that anyone is made to live in these conditions.”

NYCHA was hit with the suits a day after another group of tenants filed separate litigation alleging the authority has violated federal law by overcharging thousands of renters for at least a decade.

The Manhattan federal suit, filed by nine tenants living in different developments, also claims alleges NYCHA jacked-up rents based on faulty income calculations and wrongfully tried to boot out tenants for failing to make rent payments.

“NYCHA said Friday it is reviewing the lawsuits.”

Additional reporting by Joseph Konig