The following are the events in professional sumo during 2018.
Tournaments
Hatsu basho
Ryōgoku Kokugikan, Tokyo, 14 January – 28 January
Haru basho
Osaka Prefectural Gymnasium, Osaka, 11 March – 25 March
Natsu basho
Ryōgoku Kokugikan, Tokyo, 13 May – 27 May
Nagoya basho
Aichi Prefectural Gymnasium, Nagoya, 8 July – 22 July
Aki basho
Ryōgoku Kokugikan, Tokyo, 9 September – 23 September
Kyushu basho
Fukuoka Kokusai Center, Kyushu, 11 November – 25 November
News
January
6: The highest ranked referee, Shikimori Inosuke, is reported in the Japanese media to have apologized for sexually harassing a junior referee in a hotel in Okinawa Prefecture on December 16 last year, while drunk. 9: The three current yokozuna, Hakuhō, Kakuryū and Kisenosato, perform the traditional New Year dohyo-iri ceremony at the Meiji Shrine. 14: The Sumo Association suspend Shikimori Inosuke for three tournaments. He has already submitted his resignation, but it will not take effect until after the suspension ends in May 2018. With the other top referee title (Kimura Shonosuke) currently vacant, this will be the first time since the March 1994 tournament that neither of the head referees (tate-gyōji) will be available. 11: Kakuryū and Kisenosato, both of whom have missed some or all of the preceding four tournaments, each confirm that they will enter the forthcoming Hatsu basho. 22: Egyptian juryo division wrestler Ōsunaarashi withdraws from the tournament after reports emerge that he was involved in a rear-end motor collision at the Yamanouchi, Nagano ski resort town on January 3. Osunaarashi apparently defied the Sumo Association's ban on wrestlers driving cars, and also did not have a valid licence. He initially told police that his pregnant wife was driving and he switched seats to protect her, but back-tracked when confronted with security video evidence. 25: A lawsuit against Kasugano Oyakata and a former member of Kasugano stable who had been convicted of assault, is publicly revealed for the first time. The victim, another former wrestler from the stable, alleges that Kasugano failed to prevent the attack and delayed medical treatment. 27: The championship is won by maegashira Tochinoshin, who defeats Shōhōzan to move to an unassailable two-win lead of 13 wins against just one loss. It is the first championship by a maegashira since Kyokutenhō in 2012. 28: On the final day of the Hatsu Basho, Tochinoshin wins again to finish on 14–1, two wins ahead of ōzeki Takayasu on 12–3. Kakuryū, the only yokozuna to complete the tournament, stops a run of four straight defeats by beating ōzeki Gōeidō to finish with a respectable 11–4 record on his comeback. Tochinoshin receives special prizes for Outstanding Performance and Technique to go with his first Emperor's Cup, while the Fighting Spirit Award is shared between top division debutants Ryūden and Abi, who both score 10–5. The jūryō division championship is won by Myōgiryū for the third time, after a playoff with Hidenoumi. Retiring this tournament are former maegashira Shōtenrō, Kitataiki and . 31: Seven promotions to the jūryō division for the March tournament in Osaka are announced. There are two newcomers, Enhō (who ties the record for fastest postwar promotion to jūryō at six tournaments) and Takayoshitoshi (meaning he and Takagenji have become the first identical twins to both be ranked as sekitori) while Yago, Terutsuyoshi, Shimanoumi, Tobizaru and Akiseyama return.