Dukes | Titles by Rank
- Dukes of Sessa
- Dukes of Seste
- Dukes of Sesto
- Dukes of Sevilla
- Dukes of Sevillano
- Dukes of Shrewsbury
- Dukes of Sicignano
- Dukes of Silesia
- Dukes of Silesia-Beuthen
- Dukes of Silesia-Brieg
- Dukes of Silesia-Brieg-Liegnitz
- Dukes of Silesia-Cosel-Namslau
- Dukes of Silesia-Glogau
- Dukes of Silesia-Glogau e Sagan
- Dukes of Silesia-Glogau-Sagan
- Dukes of Silesia-Jauer-Schweidnitz
- Dukes of Silesia-Liegnitz
- Dukes of Silesia-Liegnitz-Brieg-Wohlau
- Dukes of Silesia-Münstenberg-Oels
- Dukes of Silesia-Münsterberg
- Dukes of Silesia-Münsterberg
- Dukes of Silesia-Münsterberg-Oels
- Dukes of Silesia-Oels
- Dukes of Silesia-Oels-Namslau
- Dukes of Silesia-Oppeln
- Dukes of Silesia-Teschen
- Dukes of Silesia-Teschen
- Dukes of Silesia-Troppau-Ratibor
- Dukes of Silesia-Wohlau
- Dukes of Silva
- Dukes of Siracusa
- Dukes of Sirmio
- Dukes of Skopje
- Dukes of Smaland
- Dukes of Södermanland
- Dukes of Soissons
- Dukes of Solferino
- Dukes of Solre
- Dukes of Soma
- Dukes of Somerset-I
- Dukes of Somerset-II
- Dukes of Somerset-III
- Dukes of Somma
- Dukes of Sora
- Dukes of Sora
- Dukes of Soria
- Dukes of Soria
- Dukes of Sorrentino
- Dukes of Sotomayor
- Dukes of Southampton