Born and raised in Sudbury, Bigger attended high school at St. Charles College,^[2] and studied marketing at Cambrian College and commerce at Laurentian University.^[2] He is a Chartered Professional Accountant,^[2] and worked as an accountant and auditor for Sears Canada and the Regional Municipality of Halton^[3] until he was appointed to a three-year term as the city of Greater Sudbury's auditor general in 2009.^[4]

As auditor general, he identified significant waste in the city's management of road maintenance, including scheduling inefficiencies and overbilling by outside contractors,^[4] as well as uncovering an illegal practice of paid shift trading taking place among employees of Greater Sudbury Transit.^[4]

In 2011, Greater Sudbury City Council held an in camera meeting about whether to renew Bigger's contract for a second three-year term;^[5] during the meetings, they took the unusual step of deciding to hire an outside auditor to audit Bigger's office.^[6] Bigger's contract was renewed, but several citizens of the city filed a complaint with the Ontario Ombudsman about the closed-door meetings.^[6] Ombudsman André Marin investigated the matter, ultimately finding that council was within its right to hold a closed meeting as it was a personnel matter involving a city employee, but criticized many of the councillors in his final report for refusing to cooperate with his investigation.^[6] As a result of Marin's report, city council voted to reject any oversight from the ombudsman's office.^[6]

Bigger stated that by summer 2014, he was beginning to consider running for mayor to combat the obstruction he had faced in his role as auditor.^[2] In August, he requested a leave of absence from his job as auditor to launch a campaign for mayor.^[3] The request was granted.^[3] However, council then faced a further controversy when, rather than hiring or contracting a temporary auditor general to continue audit operations during Bigger's leave of absence, it simply suspended the office and reassigned Bigger's assistant, senior auditor Vasu Balakrishnan, to the finance department.^[7]

Bigger's campaign for mayor was based on a platform of openness, transparency and accountability.^[8] His campaign promises included identifying budget savings in order to deliver a zero property tax increase in his first year as mayor,^[8] reinstating the provincial ombudsman as the investigator of complaints about council activities,^[8] and implementing new ethics guidelines for city councillors and staff modelled on the Vaughan Accord implemented by Vaughan mayor Maurizio Bevilacqua in 2011.^[9]

On election day, Bigger garnered 46 per cent of the vote.^[8]

He was reelected to a second term in the 2018 municipal election, the first mayor to be re-elected to a second term in office since the municipal amalgamation of 2001.^[10]

In October 2022, he withdrew from the 2022 Greater Sudbury municipal election several weeks after having registered as a candidate, citing the need to spend more time with his family due to the declining health of his mother.^[11]