Prince Bertil of Sweden, Duke of Halland (Bertil Gustaf Oskar Carl Eugén; 28 February 1912 – 5 January 1997), was a Swedish royal prince and the third son of King Gustaf VI Adolf of Sweden and his first wife, Princess Margaret of Connaught. He was the paternal uncle of King Carl XVI Gustaf of Sweden, a maternal uncle of Queen Margrethe II of Denmark and Queen Anne-Marie of Greece through his sister, the late Queen Ingrid of Denmark (née Princess Ingrid of Sweden).

Bertil was born 28 February 1912 at , as the fourth of five children born to Princess Margaret of Connaught and Crown Prince Gustaf Adolf of Sweden. His siblings included: Prince Gustaf Adolf, Duke of Vasterbotten, Prince Sigvard, Duke of Uppland and Princess Ingrid and Prince Carl Johan, Duke of Dalarna.

The family lived in apartments at in , at Ulriksdal Palace near the capital in Ulriksdal and at the summer residence: Sofiero Castle in Helsingborg in the southernmost province of Sweden, Scania.

Prince Bertil was granted a very old dukedom, one that was bestowed in the Middle Ages on various Danish and Swedish royal relatives, such as Benedict, Duke of Halland. After his eldest brother Prince Gustaf Adolf died in 1947, leaving an infant son Carl Gustaf in the line of succession, and because his elder brother Sigvard had already given up his place in the succession (owing to a constitutionally unacceptable marriage), it seemed likely that Bertil could one day become regent. After Carl Gustaf became King, Bertil remained the next in line to the throne (until the birth of Crown Prince Carl Philip in 1979), and continued to act as the King's deputy.

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