Tomoki Osada (長田智希, Osada Tomoki, born 25 November 1999) is a Japanese rugby union player who plays as a centre for Japan and Saitama Wild Knights in the Japan Rugby League One.^[1][2]

Tomoki was born in Kyoto Prefecture. He captained Tōkai University Gyōsei High School to a national championship and secured a berth in an all-Japan schoolboy 15. He later stamped his authority playing for Waseda University, where, as a fresher, he positioned himself as a regular starter.^[3]

He was an integral member of the Saitama Wild Knights squad, which emerged as runners-up in the 2022–23 Japan Rugby League One – Division 1 after losing the final against Kubota Spears Funabashi Tokyo Bay, in a closely fought contest as it went down the wire with the final scoreline of 15 - 17, being tilted in favor of Kubota Spears Funabashi Tokyo Bay.^[4] He was adjudged as the rookie of the year for his notable performance in the 2022/23 Japan Rugby League One season and was also subsequently named in the league’s team of the year for the 2022/23 season.^[3]

Osada was named in Japanese squad for the 2023 World Rugby Pacific Nations Cup, a tournament which was organised for the preparation of the Pacific nations ahead of the 2023 Rugby World Cup.^[3] He made his international debut against Samoa on 22 July 2023 at the 2023 World Rugby Pacific Nations Cup.^[5][6]

He was also included in Japanese squad for the 2023 Rugby World Cup and his first World Cup match came against England in a Pool D clash which was played at Allianz Riviera.^[7][8][9] In August 2024, he was named in the 34-member Japanese squad for the 2024 World Rugby Pacific Nations Cup.^[10][11] Japan eventually emerged as runners-up to Fiji after losing by 41–17 in the Grand Final.^[12]

He was also a member of the Saitama Wild Knights squad which emerged as runners-up in the 2023–24 Japan Rugby League One – Division 1 against Toshiba Brave Lupus Tokyo.^[13][14][15]