Donnelly returned to Broadway a number of times, replacing Albert Finney in "A Day in the Death of Joe Egg" in 1968, playing Milo Tindle in Anthony Shaffer's "Sleuth" and appearing as Frederick Treves opposite David Bowie as "The Elephant Man". He also renewed his relationship with Brian Friel, appearing in the world premieres of "Volunteers" at the Abbey Theatre in 1975 and "Faith Healer" with James Mason (Longacre Theatre, NYC) in 1979 as well as the Broadway premieres of "Dancing at Lughnasa" in 1991 and "Translations" in 1995.