A city worker fired for lending her cellphone to a Rikers Island inmate was reinstated last year with more than $400,000 in back pay after a six-year fight.

Sherie Tripp had a virtually unblemished 19-year career as a standards review specialist at the Board of Correction when she visited the inmate in 2007 and let him use her cellphone to file a complaint with the inspector general.

Tripp was fired afterward, even though the inmate had been shackled and an IG investigator had asked her to put him on the phone.

In 2013, an arbitrator ruled that Tripp’s move was “an error in judgment that does not warrant termination.” But Tripp wasn’t rehired until a Supreme Court judge in 2014 concurred.

“I fought because I was unjustly fired,” Tripp told The Post.

“It was tough. I faced foreclosure. But you have to stay within the system — and the system worked for me.”