[4] He made his senior debut playing for the Senior Academy team, Toronto FC III, on August 19, 2018, in League1 Ontario against Ottawa South United, scoring a 94th minute goal, becoming the youngest ever goal scorer in League1 Ontario at the age of 15 years, 3 months.

[5] On May 13, 2021, he signed his first professional contract with Toronto FC II of USL League One to join the team for the 2021 season.

[13][14][15] He made his Major League Soccer debut on May 4, 2022, as a second half substitute against FC Cincinnati.

[16] In February 2023, he signed a two-year homegrown player contract with two option years with Toronto FC.

[17][18] After a few substitute appearances, Franklin made his first start on April 29, 2023 against New York City FC.