Otakar Nickerl (22 January 1838 – 3 September 1920) was a Czech medical doctor and entomologist who contributed to the entomology collections at the National Museum in Prague. Along with his father František Antonín Nickerl (1813–1871) and his son Otakar Nickerl Jr. (1873–1904), the three generations of Nickerls were involved in establishing the entomological collections at the National Museum. He was also a pianist and composer of some choral and solo piano pieces.