Here are several Melbourne hotels (and aparthotels) that list single / single-bed or twin (single-bed) room options — useful if you want single occupancy or a room with a single bed. I’ve included the neighbourhood and an example room type for each (check exact availability/prices for your dates when booking).

• ibis Melbourne (Hotel & Apartments) — Melbourne CBD. Example room: “Standard Room 1 Double and 1 Single Bed” / twin options. (all.accor.com)
• ibis budget Melbourne CBD — Elizabeth Street (CBD). Offers twin and small standard rooms (single/twin bedding). (all.accor.com)
• ibis budget Melbourne Airport (Tullamarine) — airport hotel with rooms that include single/twin bed layouts. (all.accor.com)
• Rydges / The Victoria Hotel (Rydges group) — CBD / Flinders area. Examples: “Heritage King Single Room” and twin rooms with King Single beds. (rydges.com)
• Holiday Inn Express (IHG) — Little Collins / Southbank locations: standard rooms list single-bed / 2 single-bed (twin) options. (ihg.com)
• Holiday Inn Melbourne — Bourke Street Mall. Standard room types include configurations with single beds / two single beds. (ihg.com)
• Adina Apartment Hotel (Flinders / Southbank) — serviced-apartment option; many one‑bedroom or studio types can be configured as 1 king OR 2 single beds. Good if you want more space. (trip.com)
• Vibe Hotel Melbourne (Southbank/Yarra) — offers King or Twin/2 single-bed room types (twin rooms). (booking.com)
• Pegasus Apart'Hotel (Melbourne CBD) — aparthotel with studio/twin options; studios can be configured as one queen or two single beds. (pegasussuites.com.au)
• Novotel Melbourne on Collins — CBD; lists “Standard Room 2 Single Beds” (twin) and other bed configurations. (novotelmelbourne.com.au)

Notes:

• “Single room” naming and bed layouts vary by property — many hotels use “twin” (two single beds) or allow a room to be set as a single bed on request. Always confirm the exact bed configuration when you book.
• If you’d like, I can search availability and prices for specific dates, or filter by area (CBD, Southbank, St Kilda), budget, or amenities (free cancellation, breakfast included, parking).