Pawel Relowicz raped his 21-year-old victim on a playing field in Hull before dumping her in the city’s main waterway, the jury at Sheffield Crown Court heard.
Ms Squire’s body was found in the Humber estuary almost seven weeks after she had been reported missing following a night out on 1 February 2019.
While pathologists were unable to confirm how she died due to the length of time her body remained in the water, Relowicz was found guilty by the jury after hearing a mass of circumstantial evidence linking Relowicz to Ms Squire’s disappearance.
He will be sentenced on Friday.
Lisa Squire, the victim’s mother, said the conviction “changes nothing” for her family.
“There is no closure, we don’t get to have Libby back, our lives don’t revert back to normal”, she added.
“Libby will always be with us and we are all so proud of our beautiful, caring, wonderful girl and although she has been physically taken from us, the memories we have, and the love we share, will never be taken.”
Over the course of the three week trial the jury heard how the philosophy student had been out with friends, but was so drunk she was refused entry to a club.
After friends had paid for her to take a taxi home she did not enter her shared student house, instead walking along the streets , falling over in the snow and refusing help from passers-by until she encountered Relowicz.
Relowicz, who admitted to a number of sexual offences after his arrest, told the jury he did not kill Ms Squire and said he had consensual sex with her on Oak Road.
Over the course of the trial the defendant admitted to a series of what his barrister called “utterly disgusting” sexual offences in the months before that night – while also confessing to having watched porn and masturbated in the street in the hours after he said he had sex with the student.
Relowicz, who has convictions for outraging public decency, voyeurism and sexually motivated burglaries, said he had parked on Haworth Street with the intention of looking through windows and masturbating.
Giving evidence through an interpreter, the Polish-born defendant told the court he was driving around Hull on the evening of Ms Squire’s disappearance because he was “looking for a woman to have easy sex”, and claimed he had left Ms Squire alive on Oak Road to walk home after their encounter.
The Crown Prosecution Service said Relowicz had invented a “web of lies” after taking advantage of Ms Squire’s “vulnerable and distressed” state.
Gerry Wareham, of the CPS, said: “Relowicz robbed a young and vibrant woman of her life and her future. His actions have left her family and friends devastated.
“Relowicz invented a web of lies to explain his actions that night, insisting throughout that he had tried to help Libby find her way home.
“Nothing could be further from the truth. Far from being a good Samaritan, Relowicz preyed upon her, he took advantage of her vulnerable and distressed state and then he raped and murdered her.
“I cannot begin to imagine the suffering Libby’s family are enduring. I can only hope that today’s verdict can bring them some measure of comfort. Our thoughts remain with them.”