John Cullum (born March 2, 1930) is an American actor and singer. He has appeared in many stage musicals and dramas, including Shenandoah (1975) and On the Twentieth Century (1978), winning the Tony Award for Best Leading Actor in a Musical for each. In 1966 he gained his first Tony nomination as the lead in On a Clear Day You Can See Forever, in which he introduced the title song, and more recently received Tony nominations for Urinetown The Musical (2002) (Best Actor in a Musical) and as Best Featured Actor in the revival of 110 in the Shade (2007).
Some of his other notable roles included tavern owner Holling Vincoeur in the television drama series Northern Exposure, gaining an Emmy Award nomination (Best Supporting Actor in a Drama). He was featured in fifteen episodes of the NBC television series ER as Mark Greene's father. He also played the farmer, Jim Dahlberg, in the landmark television drama The Day After. He has made multiple guest appearances on Law & Order and Law & Order: Special Victims Unit as attorney, now judge, Barry Moredock, and appeared as Big Mike in several episodes of The Middle. He also appeared as Senator Beau Carpenter on the CBS series, Madam Secretary.