November 19, 1993|
|Height||6 ft 0 in (183 cm)|
|Weight||176 lb (80 kg; 12 st 8 lb)|
On September 9, 2019, Rantakari was signed to a four-month tryout by HC Davos of the Swiss National League (NL) through December 31, 2019. On November 30, 2019, Rantakari was signed to a one-year contract by Davos through the end of the 2019/20 season. On January 21, 2020, Rantakari was loaned to EHC Biel to replace injured Anssi Salmela.
On 18 June 2020, Rantakari left Switzerland as a free agent and agreed to a one-year deal with Russian club, HC Neftekhimik Nizhnekamsk of the KHL.
- "Otso Rantakari player profile" (in Finnish). jatkoaika.com. May 3, 2016. Retrieved May 3, 2016. CS1 maint: discouraged parameter (link)
- "Rantakari becomes a player with Neftekhimik" (in Russian). HC Neftekhimik Nizhnekamsk. June 18, 2020. Retrieved June 18, 2020. CS1 maint: discouraged parameter (link)