jˈoʊhɑːn ˈɜːnɪst ɹˌoʊmən fˈoːɹ, dˈuːk ʌv sˈækskˈoʊbɜːɡsˈɑːlfɛld twˈɛnti tˈuː ˈɔːɡəst wˈʌn θˈaʊzənd sˈɪkshˈʌndɹɪd fˈɪfti ˈeɪt ɪn ɡˈɑːθə sˈɛvəntˌiːn fˈɛbɹuːˌɛɹi wˈʌn θˈaʊzənd sˈɛvənhˈʌndɹɪd twˈɛnti nˈaɪn ɪn sˈɑːlfɛld wʌzɐ ɹˈeɪnɪŋ dˈuːk ʌv sˈækskˈoʊbɜːɡsˈɑːlfɛld.
Johann Ernest IV, Duke of Saxe-Coburg-Saalfeld (22 August 1658 in Gotha – 17 February 1729 in Saalfeld) was a reigning duke of Saxe-Coburg-Saalfeld.