Staggs was born in Wellington, New South Wales, Australia and is of Indigenous Australian (Wiradjuri people) and Tongan descent.

[citation needed] His sister Kaneesha Staggs is an Australian representative rugby union footballer who plays for the Queensland Reds.

Staggs was showing great performances for the Dolphins in the early rounds, bouncing between Centre and Second-Row, his versatility catching the eye of Broncos coach Wayne Bennett to include him into the full-time squad.

[5][6] In the lead-up to the Broncos clash against the Sydney Roosters in Round 11 of the 2018 NRL season, Staggs was selected to make his NRL debut for the Brisbane Broncos off the interchange bench after Bennett originally selected young centre Gehamat Shibasaki for the bench role but went with Staggs instead before his versatility to play in the backs and forwards.

[2][7] During the match, after Broncos fill in centre Tom Opacic suffered a concussion in only the second minute, Staggs come on to cover as centre and had an impressive debut, scoring a try, setting up a try for winger Corey Oates, running for 57 metres, made nine tackles and recorded five tackle busts during the Broncos thrilling 28–22 win at Suncorp Stadium.

On July 7, 2019, Staggs kicked 4 conversions from 4 attempts in the "Baby Broncos"' crucial 2-point win over the Cronulla-Sutherland Sharks in round 16.

Staggs played in the club's elimination final against Parramatta which Brisbane lost 58–0 at the new Western Sydney Stadium.

"The Brisbane Broncos have been made aware of a video recording involving Kotoni Staggs being circulated on social media," the statement read.