Christina Adriana Arendina (Dina) Koudijs-Appeldoorn (26 December 1884 in Rotterdam, the Netherlands – 4 December 1938 in The Hague) was a Dutch composer and pianist whose works, such as her two symphonic poems Noordzee-symfonie and Volkfeest, were written in the Romantic style. She also had a predilection for programme music, as is evidenced by her four movement suite Woudsproke.
Her works for amateur singers and choruses have been described as energetic. In them, Appeldoorn used simple tonal melodies and set the texts predominantly syllabically. In contrast, her accompaniments show a spicy harmonic language filled with dissonances which illustrate the text, such as in Frissche bloemen.