Mathilda Valeria Beatrix d'Orozco also by marriage known as Cenami, Montgomery-Cederhjelm and Gyllenhaal, (14 June 1796 – 19 October 1863) was a Swedish (originally Spanish-Italian) noble and salonist, composer, poet, writer, singer, amateur actress and harpsichordist. In Sweden, she is perhaps most known under the name Mathilda Montgomery-Cederhjelm.
Mathilda was born in Italy to the Spanish ambassador in Milan, Count Nicolas Blasco d'Orozco and Sabina Lederer. She was first married to marquess Cenami, Stable Master of the court of the sister of Napoleon, Princess Elisa Bonaparte. She was widowed before she was twenty. In 1817 in Vienna, she married second to the Swedish Count colonel Josias Montgomery-Cederhjelm (d. 1825), with whom she had four children. In 1839, she married the Swedish Baron Carl Alexander Fredrik Gyllenhaal.
In connection with her second marriage (1817), Mathilda d'Orozco moved to Sweden, where she was to live the rest of her life. In Sweden, she became a noted socialite in the capital, later called "one of the most noted ornaments in the salons of high society during the first happy and vibrant period of the reign of Charles XIV John" (reign 1818–1844). Used to the warmer climate of Italy, she once remarked : "God was angry when he created the Swedish climate!" She was described as a warm person with great charm and talent within many fields of art, which she developed in her hectic social life. As a member of the nobility, she was presented at the royal court, and took part in the court life of King Charles John and Queen Désirée, where she became a centre of the court's entertainment. She was an admired, versatile singer, who sometimes accompanied her singing by playing the harp; she also took part in the amateur theatre of the royal court, where she was described as an actress hors ligne, and was seen as a natural, fairylike dancer. The Crown Prince, Oscar, as well as the British ambassador John Bloomfield, 2nd Baron Bloomfield were counted among her admirers. After her third marriage (1839), she withdrew from society life and moved to her husband's estate out in the countryside, except for annual visits to the Norrtälje seaside resort. She died, aged 67, at Stora Ekeby, Rytterne, Sweden.
Gustaf Lagerbjelke dedicated to her the poem "L'une et l'autre".
- Den bedragne (in Swedish: The deceived) - song and music
- Husar-marsch (in Swedish: Hussar march) - Norstedt & söner, Stockholm (1854)
- La Serenata Contadinesca con risporta dalla Finestra (in Italian) - song and music
- Sex Sånger för Piano tillägnade fröken Marie von Stedingk (In Swedish: Six songs for piano in dedication to Miss Marie von Stedingk) - Songs for Piano (1842)
- Vid Julbrasan för några år sedan (In Swedish: At the Christmas fire many years ago) - song and music
- Europas konstnärer (Swedish)
- Anteckningar om svenska qvinnor (Swedish)
- Svenskt biografiskt handlexikon (Swedish)