The Baltimore Ravens signed Mekari as an undrafted free agent, as he was not selected in the 2019 NFL draft.[2] After a strong camp and preseason while showing off his versatility, Mekari made the Ravens initial 53-man roster, extending the streak of undrafted players making the Ravens roster to 16 years.[3][4]
During the 2020 season, Mekari was placed on the reserve/COVID-19 list by the team on November 25, 2020,[6] and activated on December 4, 2020.[7]
The 2021 season saw Mekari become the Ravens' starting right tackle after injuries to starting left tackle Ronnie Stanley and starting left guard/backup right tackle Tyre Phillips in Week 1. Starting right tackle Alejandro Villanueva shifted to left tackle in place of Stanley, which opened the door for Mekari to be the starting right tackle the majority of the rest of the season.
On December 30, 2021, Mekari signed a three-year contract extension with the Ravens.[8]