The 35-year-old former Tapton School pupil's victory in the general election was one of the headline results of a general election which was not short on surprises.
But amid the elation of turning the constituency red for the first time in its history, he said he couldn't help but feel compassion for the former Liberal Democrat leader, who he said was left close to tears by the defeat.
Speaking on BBC Radio Sheffield this morning, Mr O'Mara said: "I disagreed with everything he did while he was in the coalition government as deputy prime minister, particularly what he did to our students and his betrayal of them.
"I also disagreed with everything he did to our disabled people that he was complicit in while not leading on that.
"But it's impossible, human being to human being, to not be empathetic when someone was really upset, gutted and close to tears.
"People forget sometimes you might not agree with what politicians do but politicians are human and we're all subject to the same emotions. We're all subject to stress, anxiety and depression."
He added that speaking to Mr Clegg after the result was announced, he had found him 'very humble and encouraging'.
Mr O'Mara, who has cerebral palsy, which affects his movement, coordination and speech, also opened up about living with the condition.
"It's not been easy at all, particularly because I don't look conventionally disabled and a lot of people mistake me for not having a disability," he said.
But while some people might think he had got the position out of 'tokenism', he added, the true reason was 'because I care, I really do'.
He also spoke about how he had been affected by mental health problems.
He said there was a 'global pandemic' of people suffering with mental health problems and he wanted to make it easier for them to seek help.
"I want to create this discourse where people can be comfortable with their frailties. It's an issue of the human condition," he said.
Mr Clegg previously told BBC Radio Sheffield how he believed his staunchly anti-Brexit stance may have cost him his seat by convincing a number of voters in the constituency to desert the Lib Dems for the Tories.