It is a good idea to book early, the dates are popular!
There are several hotels within walking distance from the conference venue, the University Main Building (see #1 in the below map). The listed hotels were mainly chosen based on distance. Other options may be found, e.g., via Tripadvisor (https://www.tripadvisor.com). Airbnb (https://www.airbnb.com) may also be a good option, if you for example travel in a group.
Radisson Blu Aleksanteri Hotel, Albertinkatu 34, distance from the venue 1.09 km
Hotel Indigo Helsinki-Boulevard, Bulevardi 26, distance from the venue 0.96 km
Hotel Katajanokka, Merikasarminkatu 1A, distance from the venue 1.12 km
Radisson Blu Royal Hotel, Runeberginkatu 2, distance from the venue 1.09 km
Hotel Fabian, Fabianinkatu 7, distance from the venue 0.59 km
Radisson Blu Plaza Hotel, Mikonkatu 23, distance from the venue 0.41 km
Glo Hotel Kluuvi, Kluuvikatu 4, distance from the venue 0.16 km
Hotel Lilla Roberts, Pieni Roobertinkatu 1, distance from the venue 0.58 km
Hotel Rivoli Jardin, Kasarmikatu 40, distance from the venue 0.43 km
Hotel Kämp, Pohjoisesplanadi 29, distance from the venue 0.22 km
Hotel Haven, Unioninkatu 17, distance from the venue 0.35 km
Hotel F6, Fabianinkatu 6, distance from the venue 0.36 km
Hotel Klaus K, Bulevardi 2, distance from the venue 0.52 km
Holiday Inn Helsinki City Centre, Elielinaukio 5, distance from the venue 0.65 km
Hotel Helka, Pohjoinen Rautatiekatu 23, distance from the venue 1.21 km
Hotel Finn, Kalevankatu 3 B, distance from the venue 0.58 km
Omena Hotel Helsinki City Centre, Yrjönkatu 30, distance from the venue 0.69 km
Omena Hotel Helsinki Lönnrotinkatu, Lönnrotinkatu 13, distance from the venue 0.85 km
The Yard Concept Hostel, Kalevankatu 3, distance from the venue 0.58 km
Hostel Diana Park, Uudenmaankatu 9, distance from the venue 0.65 km
Eurohostel, Linnankatu 9, distance from the venue 1.20 km
Hostel Domus Academica, Hietaniemenkatu 14, distance from the venue 1.48 km