Family, friends and politicians from both major parties are attending her funeral at St Patrick's Cathedral in Melbourne on Monday afternoon.
Senator Kitching died from a suspected heart attack in the Melbourne suburb of Strathmore on March 10. She was driving and pulled over after becoming unwell.
Close friend and former Labor leader Bill Shorten, Liberal senator Bridget McKenzie, Victorian Liberal MP Tim Smith, Labor MPs Anne Aly, Madeleine King and Tony Burke were all seen arriving at the cathedral.
Labor senator Don Farrell opened the service by reading out a tribute from Senate president Slade Brockman.
"Kimberley was an exemplar of a senator, using her role within the Senate and its committees in driving policy change," he told those gathered.
"Kimberley brought to Australian politics a worldview that transcended narrow partisan boundaries.
"She had a clear moral compass, to which she always held true. She believed in and championed Australian democracy."
Opposition Leader Anthony Albanese remembered Senator Kitching as "formidable, passionate and courageous" in a tweet ahead of the funeral.
"Kimberley Kitching's friends, family, and colleagues from across the parliament will gather to honour and celebrate her life," he tweeted.
"She was the life of any room she walked into. She will be missed by those who knew her, and many more who didn't."
In the wake of her death, reports have emerged the senator was ostracised and bullied by members of Labor's Senate leadership team.
Prime Minister Scott Morrison said his thoughts were with Senator Kitching's family, but indicated Mr Albanese had questions to answers about her treatment in parliament.
"When (Anthony Albanese) has to deal with the same issues in his own house, well, he shuts up shop and gets into the basement," he told Brisbane radio station 4BC.
However, Labor frontbencher Mark Butler said the funeral should be a day to celebrate her life, not to bring up divisive issues.
"Today of all days is not to go into a number of the claims being made and things being said over recent days," he told ABC Radio.
"Today is a day for the people who knew Kimberley to get around each other, hug each other and celebrate an extraordinary life that was ended far too early."
6°C