5) Thomas Frank (Brentford) – 3 Years And 122 Days
The eccentric Dane has done an excellent job after taking over from Dean Smith. He helped the Bees finish eleventh after Smith left for Aston Villa in 2018, before he guided them to a third-place finish during his first full season in charge.
After losing out in the playoffs in 2020, Brentford made another attempt to gain promotion last year and they succeeded. Frank’s team have done very well in their first Premier League campaign, currently sitting 14th in the table.