[1]: 1071 Noted for his girth and cultured voice, Avery usually played sophisticated and articulate villains, including the featured nemesis in six out of seven episode appearances on the ABC/Warner Brothers western television series Maverick starring James Garner, Jack Kelly and Roger Moore between 1957 and 1962.

[citation needed] In 1960, he was cast as Theodore and John Nichols, respectively, in the episodes "Key to the City" and "False Identity" of the ABC/WB crime drama, Bourbon Street Beat starring Andrew Duggan, Richard Long and Van Williams.

"[citation needed] That same year, he was cast as "Speaker Bert Metcalf" on the CBS drama series Slattery's People, starring Richard Crenna.

In 1966, Avery appeared three times on the syndicated western anthology series, Death Valley Days, as Frank Brenner in "The Resurrection of Deadwood Dick" and as Walter Benson in "Doc Holliday's Gold Bars" (both 1966), and as judge Sidney Edgerton, who later becomes the first governor of the Montana Territory, in the segment "Lucia Darling and the Ostrich" (1969).

One of his last appearances was as Justice Redding in the 1973 TV-movie The Marcus-Nelson Murders, which served as the pilot for the CBS detective series Kojak, starring Telly Savalas.