| Albert IV | |
| Succession: | Duke of Saxe-Bergedorf-Mölln |
| Reign: | 1321–1343 |
| Reign-Type: | Reign |
| Predecessor: | John II of Saxe-Lauenburg |
| Pre-Type: | Predecessor |
| Successor: | John III of Saxe-Lauenburg |
| Suc-Type: | Successor |
| Spouse: | (1) Beata of Schwerin (2) Sophia of Werle-Güstrow |
| Issue: | John III Albert V Eric III |
| Issue-Link: | Albert IV of Saxe-Lauenburg#Marriages and issue |
| House: | Ascania (by birth) |
| House-Type: | House of |
| Father: | John II of Saxe-Lauenburg |
| Mother: | Elisabeth of Schauenburg and Holstein-Rendsburg |
| Birth Date: | 1315 |
| Death Date: | 1343 |
Albert IV of Saxe-Lauenburg (1315 – 1343) was the eldest son of John II of Saxe-Lauenburg and Elisabeth of Holstein-Rendsburg (*ca. 1300–before 1340*), sister of Gerard III the Great. In 1321 Albert IV succeeded his father as Duke of Saxe-Bergedorf-Mölln, a branch duchy of Saxe-Lauenburg, while his mother served as regent, before she remarried Eric Christoffersen (*1307–1331*), a son of King Christopher II and co-ruler in Denmark.
Albert married twice, in 1334 (1) Beata of Schwerin (*?–before 1341*), daughter of Gunzelin VI, Count of Schwerin, and in 1341 (2) Sophia of Werle-Güstrow (*1329–5 September 1364*), daughter of Lord John II of Werle-Güstrow. Both wives also officiated as Saxon consorts. With Beata Albert had the following children:
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