At the World Athletics Championships, Miller-Uibo won silver medals in the 400 m in 2015 and 2019, and a bronze at the 200 m in 2017 when she also placed fourth at her longer distance.

Her marks of 48.36 (improved at the Tokyo Games) and 50.21 seconds place her respectively sixth and joint eighth on the world all-time list.

Miller-Uibo holds the world's fastest women's marks in straight races of 150 m and 200 m. Her personal best of 21.74 s for the 200 m is a Bahamian national record.

Of Afro-Bahamian heritage, Miller-Uibo was born in a Christian home to Mabelene and Shaun Miller in Nassau, Bahamas, the granddaughter and niece of pastors, on 15 April 1994.

Sixteen-year-old Miller-Uibo became the first Bahamian to be 400 m champion at the 2010 World Junior Championships in Athletics and the youngest woman to ever win the event.

In her last age category competition, she won three gold medals (200 m, 400 m, 4 × 100 metres relay) at the 2013 CARIFTA Games and was given the Austin Sealy Award as the best athlete of the tournament.

The year after, Miller-Uibo won her first senior medal, finishing behind Francena McCorory and Kaliese Spencer in the 400 m at the 2014 IAAF World Indoor Championships.

The 2015 season marked her first impact at the Diamond League, as she won the 400 m at the top level Athletissima and Memorial Van Damme meets.

[15][16] The winner of the event, Salwa Eid Naser, was provisionally suspended by the Athletics Integrity Unit in June 2020 for missing four anti-doping tests in 12 months, the last of which was in January 2020.

[20][21] Miller met Maicel Uibo, an Estonian decathlete who won silver at the 2019 World Championships in Georgia, and the pair married in 2017.