On 11 December 2016 Atlanta United FC acquired Williams from the Impact in exchange for a third-round selection in the 2018 MLS SuperDraft.[7] On 7 April 2018, he scored his first career MLS goal in a 5–0 rout of Los Angeles FC.
On 1 July 2019, Williams was traded to Columbus Crew SC in exchange for $100,000 of General Allocation Money.[8] After one season with the crew, Williams joined Miami FC of the USL Championship in January 2020.[9]
On 4 January 2024, Williams signed with Hartford Athletic.[14] In the season opener and his debut with the club on 9 March, Williams would slot in a penalty to score his first goal for Hartford and help them defeat El Paso Locomotive in a 1–0 win.[15] Williams made 12 total league and cup appearances for Hartford in 2024, scoring 3 goals.[16]
Williams has represented the U-17 level of the Jamaica national U-17 team, playing in three games at the 2011 U17 FIFA World Cup. He had previously started four of five games at the CONCACAF qualifiers. Romario also played the Jamaica U-23 national team in March 2015.[21] Williams made his Jamaica senior national team debut in a 1–0 Caribbean Cup qualify win over Suriname on 13 November 2016.[22]
Personal
He was named after Romário, Brazilian football legend who won the 1994 FIFA World Cup a month before he was born.
In February 2018, Williams received a U.S. green card which qualifies him as a domestic player for MLS roster purposes.[23]