Theodore Samuel Holland, OBE (25 April 1878 – 29 October 1947), was a British composer and academic.
Holland was born in Wimbledon, London and was educated at Westminster School before moving to the Royal Academy of Music, where he studied with Frederick Corder. He later studied with Joseph Joachim at the Musikhochschule in Berlin.
Holland initially pursued a career in the theatre, but he won two mentions in dispatches and an OBE for his services during the Great War. The war, however, left him shell-shocked, a condition with which he suffered for the rest of his life.
In 1927 Holland was appointed Professor of Harmony and Counterpoint at the Royal Academy of Music, a position he would hold until he died. His professional duties included those of Treasurer of the Royal Musical Association and as a member on the committees of the Royal Philharmonic Society and the Incorporated Society of Musicians.
His students included Iris du Pré, mother of cellist Jacqueline du Pré. Lessons were held in the music room at the top of his London home in Eldon Road, Kensington, also the scene of regular concerts and musical gatherings. Holland's wife Isména became godmother to the young cellist. Much younger that her husband, Isména survived him by nearly 60 years. She died in October 2004, aged 101. 
His early theatre compositions included incidental music for Shakespeare's The Two Gentlemen of Verona, additional songs for Leo Fall's operetta The Merry Farmer (1907) and the children's opera King Goldemar (1902). But Holland composed in almost all major classical forms. For orchestra he wrote Gavotte Pastorale, the tone poem Evening on the Lake (1908), a violin concerto in one movement, Ellingham Marshes for viola and orchestra,  the Spring Sinfonietta (1943) and the Threnody for cello and orchestra (1945), which was not performed until three years after the composer's death, at a concert in Watford. 
String quartets in C minor and E minor were published in 1933 and 1938, and piano trios in 1935 and 1943.. He also wrote Cortege for four cellos (1939, published 1941) and a Suite in D for viola and piano (1938). Miniatures for violin and piano included Four Fancies (1923), Fireflies (Op. 18/20), the Variations (1927) and Autumn Voices written just prior to his death..
Holland's music for solo piano, included Variations on a Swedish Air (1906), and Preludes (1944). A number of his works used remote keys, including Toccata in E-flat minor, the Sonatina in F-sharp minor (both 1938), and the Variations on an Original Theme, also in F-sharp minor.
Song compositions included the Opus 4 and Opus 6 sets, set to German words, two Shelley songs (1908) and three Flecker songs (1938). Philip Scowcroft considers his most important vocal items to be The Songs from Nyasaland (Opus 20), for voice and orchestra, published with piano accompaniment, and the cantata A Pastoral Medley.
Holland's style has been described as "idiosyncratic and colourful" and as "best suited to theatre". However, a small number of his concert works achieved moderate success. A suite based on music for a children's play, Santa Claus (produced at the London Scala in 1912) was frequently broadcast at Christmas time during the 1920s and 1930s. His Trio in E minor, performed by the Grinke Trio, was broadcast on the BBC Home Service in 1935  and again in 1940.  Ellingham Marshes for viola and orchestra was given its première at the Proms on 15 April 1940 and broadcast by the BBC on 7 April 1941. A modern recording was issued by Dutton in 2012. 
- Philip L Scowcroft. "Two Academic Composers: Hugo Anson and Theodore Holland". musicweb-international.com. Retrieved 15 July 2013.
- "Theodore Holland (1878–1947)". naxos.com. Retrieved 28 June 2013.
- Jacqueline du Pré Her Life, Her Music, Her Legend by Elizabeth Wilson, 1997
- The Times, November 4, 2004, page 82.
- "Prom 05". BBC. 15 August 1940. Retrieved 18 March 2016.
- Radio Times, 25 March, 1952
- Radio Times, 8 June 1935
- Radio Times, 25 October 1940
- Presto Classical
- Last.fm page with an image of Holland
- Theodore Holland at AllMusic
- Theodore Holland discography at Discogs
- Performance of Cortége for four cellos by Quatricelli, 29 March 2015
- Barnett, Rob: Review of Ellingham Marshes (Dutton premiere recording, 2012) at Musicweb International