February 17 is the 48th day of the year in the Gregorian Calendar. It is preceded by February 16, and succeeded by February 18. Following February 17, there are 317 days in the year (318 in leap years).
- 1880 – H. S. Olcott and H. P. Blavatsky arrived in Ceylon.
- 1953 – Nilakanta Sri Ram (1889-1973), took office as the fifth international President of the Theosophical Society (Adyar).
- 1847 – date claimed by C. W. Leadbeater, as recorded on his passports, though the birth records show he was born on February 16, 1854.
- 1600 – Giordano Bruno, martyred under Diocletian; philosopher and astronomer (b. 1548)
- 1907 – Henry Steel Olcott, American attorney; Co-founder and first International President of Theosophical Society, serving from 1875-1907. (b. 1832)
- 1986 – Jiddu Krishnamurti, spiritual teacher, philosopher, and writer raised by Theosophists Annie Besant and C. W. Leadbeater (b. 1895).
Holidays and observances
- Adyar Day, honoring death of H. S. Olcott; began in 1922
- Olcott Day in Sri Lanka, celebrating that day in 1880 that H. S. Olcott and H. P. Blavatsky arrived in Ceylon.