Some notable members of this family are:
- Johan Abraham Gyllenhaal (1750–1788), geologist and mineralogist.
- Leonard Gyllenhaal (1752–1840), military officer and gentleman farmer, known as an entomologist and a leading Swedenborgian. His best-known work was his monograph on Swedish beetles, Insecta suecica. Coleoptera in 4 parts, published between 1808 and 1827.
- Carl Henrik Gyllenhaal (1788–1857), a military officer who participated in the Finnish war of 1808–1809, was later Governor of Blekinge County and Skaraborg County, Privy Councilor, and finally Director General of the Swedish customs. Created a baron in 1837.
- Lars Herman Gyllenhaal (1790–1858), Swedish Prime Minister for Justice 1843–1844. Created a baron in 1843.
- Mat(h)ilda Valeria Beatrix Gyllenhaal (1796–1863), née de Orozco, singer, composer and socialite (married in her third marriage to cavalry lieutenant baron Carl Alexander Fredrik Gyllenhaal, son of Carl Henrik G.). Matilda was a Spanish countess, born in Milan, Italy. She was first married to the stablemaster of Napoleon I's sister; in 1817, widowed, she married J. Montgomery-Cederhjelm in Vienna and became a leading figure and trendsetter in Stockholm society. In 1825 she was widowed again; she married a third time in 1839 to Carl Gyllenhaal. She was the subject of a poem by the leading Swedish poet Esaias Tegnér, and a song by Erik Gustaf Geijer; she herself wrote songs and set Tegnér's Rings Drapa to music.
- Anders Leonard Gyllenhaal (1842–1905; grandson of Leonard G.), Editor-in-chief of the Swedish-American newspaper Svenska Tribunen in Chicago. Ancestor of the American branch.
- Stephen Gyllenhaal (born 1949), film director (great grandson of Anders Leonard G.), was married to producer and screenwriter Naomi Foner Gyllenhaal.
- Anders Gyllenhaal, Washington Editor and Vice President of News, The McClatchy Company, former executive editor of the Miami Herald
- Liza Gyllenhaal Bennett (born 1953), novelist
- Lars Gyllenhaal (born 1968, great great-great grandson of Lars Herman Gyllenhaal), Swedish writer, member of the Swedish Military History Commission.
- Maggie Gyllenhaal (born 1977), Academy Award-nominated American actress (daughter of Stephen G.)
- Jake Gyllenhaal (born 1980), Academy Award-nominated American actor (son of Stephen G.)
- Sam Gyllenhaal, musician, videographer, former member of Elon University a cappella group Twisted Measure (son of Anders G.)
Nils Gunnarsson Gyllenhaal's descendants today stem from two of his sons; Lars Gyllenhaal (1645–1710), Lieutenant of the Vestgotha cavalry regiment, and his younger brother Hans Gyllenhaal (1655–1710). Hans was killed in action at the battle of Helsingborg as a cavalry captain.
The members of the older branch descending from Lars are still living in Sweden. The most notable member of that branch is the above-mentioned Minister for Justice Lars Herman Gyllenhaal. In 1851 he was created Knight and Commander of the Royal Order of the Seraphim. His great-great grandson Herman Gyllenhaal till Härlingstorp (born 1934) is now the baron of the family and his son, the above-mentioned Lars Gyllenhaal, is now the head of both branches of the noble family Gyllenhaal.
All the members of the family in the United States are descended from Hans Gyllenhaal and come from his great great-great grandson Anders Leonard (1842–1905) and his wife Amanda (née Nelson, 1859–1948). Anders Leonard Gyllenhaal immigrated to the United States in 1866. The hitherto most memorable member of this younger branch was Leonard Gyllenhaal (1752–1840). In 1807 he was created a Knight of the Royal Order of Vasa for his scientific work as an entomologist, including his monograph of Swedish insects, Insecta Suecia descripta.
The spelling of the name Gyllenhaal caused problems right from the beginning. Its origin is clear: Nils Gunnarsson Gyllenhaal's father was Gunne Olofsson Haal from Hahlegården, a crown homestead in South Härene Parish in the county of Västergötland in West Sweden. "Haal" comes from the name of the farm "Hahlegården", with different spelling. This confusion was mirrored in Nils' ennoblement: In the Knighthood Letter, signed by Queen Christina, the family name was written in two different ways — first "Gyllenhahl" and then "Gyllenhaal". On the copperplate with his coat of arms now hanging in the House of Nobility (Riddarhuset) in Stockholm it is spelled "Gyllenhahl". The prefix "Gyllen", i.e. "Golden", was the one most used when ennobling someone since the 16th century.
Jake Gyllenhaal, great-great grandson of the above-mentioned Anders Leonard Gyllenhaal, quipped during an interview prior to the British premiere of Prince of Persia that his last name was pronounced "Yil-en-hoo-luh-hay", parodying Americans' difficulties with Swedish pronunciation.
- Article on members of the Gyllenhaal family in Nordisk Familjebok
- Article on members of the Gyllenhaal family in Svenskt biografiskt handlexikon
- Johan Abraham Gyllenhaal biography on Gyllenhaal.org translated from Svenskt Biografiskt Lexikon, 1968, pages 556-558.
- Carl Henrik Gyllenhaal on gyllenhaal.org translated from Svenskt Biografiskt Lexikon, Stockholm, 1968.
- Article on Matilda Gyllenhaal in Nordisk familjebok
- Anders Leonard Gyllenhaal: Obituary said to be from Nya Svenska Amerikanen, 1905.
- Compare this with the naming of the former head of the car manufacturer Volvo Pehr Gustaf Gyllenhammar and Sofia De la Gardie.
- In the Scandinavian languages a double "aa" as in Gyllenhaal, has for centuries normally been pronounced with an "o" sound as in English "for". In this case, however, in Swedish it is pronounced with a long "a" as in the English word "far"; the double "aa", as with the "ah" in the alternative "Gyllenhahl" (see above) only indicates a long vowel "a".
- The second problem for English-speakers is how to pronounce the prefix "Gyllen", i.e. Golden. The USA branch of the family's solution is to pronounce it "Jill-EN-hall", but in Sweden "Gy" is pronounced as "Y" followed by a close front rounded vowel, similar to the German vowel "ü".