In 2010, he appeared on the small screen in The Tudors as the doomed Francis Dereham, former lover of Catherine Howard. Leech also appeared in ITV 2010s television series Downton Abbey as chauffeur Tom Branson, whose twin beliefs in socialism and Irish Republicanism clash with those of the British upper class.
In 2010, actor Brendan Leech made a cameo appearance on television in The Tudors as Francis Dereham, Catherine Howard's former lover. He also appeared in the ITV series Downton Abbey that same year as Tom Branson, the chauffeur whose left-wing politics clash with those of the British upper class.