He takes over from former Melbourne-based boss Mick Murray, who recently stepped aside over a murder charge.
Meehan, 35, grew up in public housing in Sydney's south-west and has spent his half his life rising through the bikie gang ranks.
He joined the Rebels when he turned 18 and later became a Cronulla chapter president before he defected to the Comancheros.
Sources claim he was lured to switch allegiances by a mentor, Comanchero 'commander of the world' Mark Buddle, who is one of Australia's most wanted men over the 2010 shooting of Armaguard security guard Gary Allibon in Sydney.
Buddle remains on the run from authorities overseas and was last known to be in Cyprus.
Meehan is well 'respected' among both the gang's old guard and its new recruits, the Herald Sun reported.
'He's spent his entire adult life in bikie gangs,' one source told the publication.
'He doesn't know any other life.'
He was promoted to commander of the Canberra chapter early last year after the murder of former president Pitasoni Ulavalu and became the Sydney commander six months later.
It's understood Meehan has told members he'll oversee the Comancheros from Sydney but is expected to regularly travel to Melbourne.
He was regarded as next in line to take over from Murray, 44, was arrested in April over the 2019 gangland killing of Mitat Rasimi, an associate of high-profile drug lord Tony Mokbel
He was charged with one count of murder and remains behind bars.
It's been a chaotic few months for Australia's most powerful bikie club still reeling from the recent underworld shooting which left national sergeant-at-arms Tarek Zahed with serious injuries and claimed the life of his brother Omar.
Dozens of other members have been also arrested in AFP raids as part of Operation Ironside, one of the biggest and most significant crackdowns of organised crime in Australia's history.
One source recently said Meehan was regarded as 'pretty full on' but has a level head to control some of the gang's more volatile elements.