List of heads of state 1538

Africa

( Abdalwadiden ) (in what is now western Algeria, capital Tlemcen )
- Sultan : Abu Muhammad Abdallah II (1528-1540)

Bornu (in present-day Niger ) Sefuwa dynasty
- King / May: Mohammed V (1515–1538)

Ifriqiya (East Algeria, Tunisia) ( Hafsiden )
- Caliph : Al Hassan (1526-1534) (1535-1543)

Jolof (in what is now Senegal )
- Buur-ba Jolof : Birayma Dyeme-Kumba (1527–1543)

Morocco
- Wattasids (in the north)
  - Sultan : Abu l-Abbas Ahmad (1524–1549)
- Saadier (in the south)
  - Sultan : Ahmad al-Arudsch (1517–1540)

Sultanate of Sannar (in what is now Sudan )
- Sultan : Nayil (1533 / 34–1550 / 51)

Viceroyalty of New Spain
- Viceroy : Antonio de Mendoza (1535–1550) (1551–1552 Viceroy of Peru)

India
- Mughal Empire
  - Mughal Mughal : Humayun (1530–1540) (1555–1556)

Japan
- Emperor : Go-Nara (1526–1557)
- Shogun Ashikaga : Ashikaga Yoshiharu (1521-1546)

Vietnam
- North ( Mạc dynasty )
  - King: Mạc Thái Tông (1530–1540)
- South ( Hậu Lê Dynasty )
  - King: Lê Cung Hoàng (1533–1548)

Andorra
- Co-princes :
  - King of Navarre : Henry II (1516–1555)
  - Bishop of Urgell : Francesc de Urríes (1534–1551)

Holy Roman Empire
- King and Emperor : Charles V (1519–1556) (Emperor from 1520, King of Spain 1516–1556, Archduke of Austria 1519–1521)
- Electorates
  - Archbishopric of Cologne
    - Archbishop : Hermann V. von Wied (1515–1547) (1532–1547 administrator of Paderborn)
  - Archbishopric Mainz
    - Archbishop : Albrecht von Brandenburg (1514–1545) (1513–1545 Archbishop of Magdeburg, 1513–1543 Administrator of Halberstadt)
  - Archbishopric Trier
    - Archbishop : Johann III. von Metzenhausen (1531–1540)
  - Bohemia
    - King : Ferdinand I (1526–1564)
  - Brandenburg
    - Elector : Joachim II. Hector (1535–1571)
  - Electoral Palatinate
    - Elector : Ludwig V (1508–1544)
  - Saxony ( Ernestiner )
    - Elector : Johann Friedrich I. (1532–1547/54) (from 1547 electorate to Albertine line)

Italian states
- Ferrara , Modena and Reggio
  - Duke : Ercole II. D'Este (1534–1559)
- Genoa
  - Doge : Giovanni Battista Doria (1537–1539)
- Papal States
  - Pope : Paul III. (1534-1549)
- Milan (1535–1706 to Spain )
  - Duke : Charles I of Spain (1525–1529) (1535–1540)
    - Governor : Marino Caracciolo (1536–1538)
    - Governor: Alfonso d'Avalos (1538–1546)
- Mantua and Montferrat ( Gonzaga )
  - Duke : Federico II Gonzaga (1519–1540) (until 1530 margrave)
- Massa and Carrara
  - Margravine : Ricciarda Cybo-Malaspina (1519–1546) (1547–1553)
- Naples (1503–1707 / 14 to Aragon or Spain )
  - King: Charles I of Spain (1516–1556)
    - Viceroy : Pedro Álvarez de Toledo (1532–1553)
- Saluzzo
  - Margrave : Gabriel (1537–1543 / 48)
- Savoy
  - Duke : Charles III. (1504–1553)
- Sicily (1412–1713 to Aragon or Spain )
  - King: Charles I of Spain (1516–1556)
    - Viceroy : Ferrante Gonzaga (1535–1546) (Interim)
- Tuscany
  - Duke : Cosimo I de 'Medici (1537–1574) (from 1569 Grand Duke)
- Urbino
  - Duke : Francesco Maria I della Rovere (1508–1516) (1521–1538)
  - Duke: Guidobaldo II. Della Rovere (1538–1574)
- Venice
  - Doge : Andrea Gritti (1523–1538)
  - Doge: Pietro Lando (1538–1545)

Moldova
- Prince : Petru Rareș (1527–1538) (1541–1546)
- Prince: Ștefan Lăcustă (1538–1540)

Hungary (rule disputed)
- King : Ferdinand I (1526–1564)
- King: Johann Zápolya (1526–1540)