Everyone needs a passport, onward ticket, and sufficient funds to cover their stay in the Solomon Islands.
Citizens of the following nationalities can get visitor's visas on arrival:American Samoa, Andorra, Anguilla, Antigua and Barbuda, Argentina, Aruba, Australia, Austria, Bahamas, Barbados, Belize, Bonaire, Brazil, British Virgin Islands, Brunei, Canada, Cayman Islands, Chile, Cook Islands, CuraÃ§ao, Czech Republic, Denmark, Dominica, Dominican Republic, Fiji, Finland, France, French Polynesia, Germany, Greece, Grenada, Guadeloupe, Guam, Guyana, Hungary, Iceland, Ireland, Israel, Italy, Japan, South Korea, Kuwait, Liechtenstein, Luxembourg, Malaysia, Maldives, Malta, Marshall Islands, Martinique, Federated States of Micronesia, Monaco, Montserrat, Nauru, Netherlands, New Caledonia, New Zealand, Niue, Norfolk Island, Northern Mariana Islands, Norway, Palau, Papua New Guinea, Paraguay, Peru, Pitcairn Islands, Poland, Portugal, Puerto Rico, Saba, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Samoa, San Marino, Singapore, Slovakia, Slovenia, Spain, Suriname, Sweden, Switzerland, Taiwan, Thailand, Tonga, Trinidad and Tobago, United Kingdom, United States, Uruguay, Vanuatu, Wallis and Futuna.
Everyone else will need a visa in advance.
If you have a visitor's permit, you are not allowed to engage in work, business, religious vocations, or professional research. If you wish to do any of those things, you must get a business permit.