The Portland Symphony Orchestra has had 13 main conductors since its establishment in 1923. Its first conductor was the city of Portland's organist, Charles Raymond Cronham, from 1927 to 1932. During his tenure, he extended rehearsals and the concert schedule. He also inaugurated out-of-town concerts such as the performance at Bowdoin College in January 1928. Volunteers and musicians transported the orchestra and all its instruments, including two pianos.
In 1933, a school of music supervisor, Charles A. Warren, from Brunswick took over for a year.
From 1935 to 1937, Paul E. Melrose was the main conductor. He was part of the 5th US Infantry Band at Fort Williams as the warrant officer and band leader.
Dr. Russell Ames Cook was the first out-of-state conductor. An outgoing man, he befriended the "leading families" of the orchestra, and they helped him get support. During his tenure from 1938 until 1951, there was an increase in donations, supporters, and volunteers which were all essential to its success.
In 1952, the concertmaster and associate conductor of the Boston Symphony Orchestra, Richard Burgin, became the PSO's conductor. His legacy was to help improve the string section.
Rouben Gregorian took over in 1958, after Burgin's administration ended. He was a graduate of Central College in Iran, where he had been the co-founder and conductor of the Tehran Symphony Orchestra. As the main conductor of the Portland Symphony Orchestra, he finalized the enactment of a fully paid orchestra in 1959.
In 1962, Arthur Bennett Lipkin began his tenure. He was the first resident conductor and began the youth concerts. The orchestra was involved with Voice of America broadcasts, including a broadcast to Kyoto, Japan.
From 1967 until 1975, Paul Vermal was the main conductor. He conducted a five-day Canadian Tour. He also introduced outdoor concerts and concert previews.
The Portland Symphony Orchestra developed a national reputation for its artistic quality during Bruce Hangen's subsequent tenure. He helped expand educational programs which attracted children of all ages. He also created and developed the Portland Symphony Chamber Orchestra. His administration lasted from 1976 until 1986.
Toshiyuki Shimada took over in 1986. He tightened the orchestra's grasp of symphonic masterworks and deepened its commitment to youth and family programming, while building higher on the firm music foundations left by his predecessors.
Robert Moody was the 12th music director of the Portland Symphony from 2008 until 2018. He was a champion of new music, particularly the work of Mason Bates, and began the Discovery Concert series for families.
Eckart Preu has been named the 13th music director of the Portland Symphony and began his tenurein the 2019–2020 season.
1956–1958 guest conductors:
- Samuel Seineger
- Rouben Gregorian
- Attilio Poto
- Francis Findlay
1966–1967 guest conductors:
- Charles Gabor
- Elyakum Shapiro
- Maurice Kaplow
- Andrew Galos
- Paul Vermel
1975–1976 guest conductors:
- Michael Palmer
- Michael Charry
- Claude Monteux
- Bruce Hangen
- Maurice Kaplow
- Richard Williams
- Tibor Pusztai
1985–1986 guest conductors:
- Robert Bernhardt
- Toshiyuki Shimada
- Robert Page
- Catherine Comet
- Paul Polivnick
