Knowing all available Odoo module categories will help developers choose a suitable one to place their module in.
Category of a module can be defined in __manifest__.py of your module folder.
'category': 'Uncategorized',
The full list can be found at addons\base\data\ir_module_category_data.xml
.

<record model="ir.module.category" id="module_category_hidden"> <field name="name">Technical Settings</field> <field name="sequence">0</field> <field name="visible" eval="0" /> </record> <record model="ir.module.category" id="module_category_localization"> <field name="name">Localization</field> <field name="visible" eval="0" /> </record> <record model="ir.module.category" id="module_category_localization_account_charts"> <field name="parent_id" ref="module_category_localization" /> <field name="name">Account Charts</field> <field name="visible" eval="0" /> </record> <record model="ir.module.category" id="module_category_sales_management"> <field name="name">Sales</field> <field name="description">Helps you handle your quotations, sale orders and invoicing.</field> <field name="sequence">1</field> </record> <record model="ir.module.category" id="module_category_lead_automation"> <field name="name">Lead Automation</field> <field name="description">Helps you manage lead of your marketing campaigns step by step.</field> <field name="sequence">2</field> </record> <record model="ir.module.category" id="module_category_project_management"> <field name="name">Project</field> <field name="description">Helps you manage your projects and tasks by tracking them, generating plannings, etc...</field> <field name="sequence">3</field> </record> <record model="ir.module.category" id="module_category_warehouse_management"> <field name="name">Inventory</field> <field name="description">Helps you manage your inventory and main stock operations: delivery orders, receptions, etc.</field> <field name="sequence">4</field> </record> <record model="ir.module.category" id="module_category_manufacturing"> <field name="name">Manufacturing</field> <field name="description">Helps you manage your manufacturing processes and generate reports on those processes.</field> <field name="sequence">5</field> </record> <record model="ir.module.category" id="module_category_account_voucher"> <field name="name">Invoicing & Payments</field> <field name="description">Allows you to create your invoices and track the payments. It is an easier version of the accounting module for managers who are not accountants.</field> <field name="sequence">6</field> </record> <record model="ir.module.category" id="module_category_accounting_and_finance"> <field name="name">Accounting & Finance</field> <field name="description">Helps you handle your accounting needs, if you are not an accountant, we suggest you to install only the Invoicing.</field> <field name="sequence">7</field> </record> <record model="ir.module.category" id="module_category_purchase_management"> <field name="name">Purchases</field> <field name="description">Helps you manage your purchase-related processes such as requests for quotations, supplier bills, etc...</field> <field name="sequence">8</field> </record> <record model="ir.module.category" id="module_category_user_type"> <field name="name">User types</field> <field name="description">Helps you manage users.</field> <field name="sequence">9</field> </record> <record model="ir.module.category" id="module_category_human_resources"> <field name="name">Employees</field> <field name="description">Helps you manage your employees.</field> <field name="sequence">9</field> </record> <record model="ir.module.category" id="module_category_hr_holidays"> <field name="name">Leaves</field> <field name="description">Helps you manage your leaves.</field> <field name="sequence">10</field> </record> <record model="ir.module.category" id="module_category_hr_contract"> <field name="name">Contracts</field> <field name="description">Helps you manage your contracts.</field> <field name="sequence">10</field> </record> <record model="ir.module.category" id="module_category_hr_recruitment"> <field name="name">Recruitment</field> <field name="description">Helps you manage your recruitments.</field> <field name="sequence">11</field> </record> <record model="ir.module.category" id="module_category_hr_expense"> <field name="name">Expenses</field> <field name="description">Helps you manage your expenses.</field> <field name="sequence">12</field> </record> <record model="ir.module.category" id="module_category_hr_timesheet"> <field name="name">Timesheets</field> <field name="description">Helps you manage the timesheets.</field> <field name="sequence">13</field> </record> <record model="ir.module.category" id="module_category_hr_attendance"> <field name="name">Attendance</field> <field name="description">Helps you manage the attendances.</field> <field name="sequence">14</field> </record> <record model="ir.module.category" id="module_category_hr_appraisal"> <field name="name">Appraisals</field> <field name="description">Helps you manage your appraisals.</field> <field name="sequence">15</field> </record> <record model="ir.module.category" id="module_category_hr_payroll"> <field name="name">Payroll</field> <field name="description">Helps you manage your payrolls.</field> <field name="sequence">16</field> </record> <record model="ir.module.category" id="module_category_hr_gamification"> <field name="name">Gamification</field> <field name="description">Helps you manage the gamification process.</field> <field name="sequence">17</field> </record> <record model="ir.module.category" id="module_category_event_management"> <field name="name">Events</field> <field name="description">Helps you manage your Events.</field> <field name="sequence">18</field> </record> <record id="module_category_mass_mailing" model="ir.module.category"> <field name="name">Email Marketing</field> <field name="sequence">19</field> <field name="description">Helps you manage your mass mailing for design professional emails and reuse templates.</field> </record> <record id="module_category_survey" model="ir.module.category"> <field name="name">Survey</field> <field name="description">Helps you manage your survey for review of different-different users.</field> <field name="sequence">20</field> </record> <record model="ir.module.category" id="module_category_point_of_sale"> <field name="name">Point of Sale</field> <field name="description">Helps you get the most out of your points of sale with fast sale encoding, simplified payment mode encoding, automatic picking lists generation and more.</field> <field name="sequence">21</field> </record> <record model="ir.module.category" id="module_category_specific_industry_applications"> <field name="name">Specific Industry Applications</field> <field name="sequence">22</field> </record> <record model="ir.module.category" id="module_category_website"> <field name="name">Website</field> <field name="sequence">23</field> </record> <record model="ir.module.category" id="module_category_sign"> <field name="name">Document Signatures</field> <field name="description">Helps you sign and complete your documents easily.</field> <field name="sequence">25</field> </record> <record model="ir.module.category" id="module_category_helpdesk"> <field name="name">After-Sales</field> <field name="description">After-sales services</field> <field name="sequence">2</field> </record> <record model="ir.module.category" id="module_category_theme"> <field name="name">Theme</field> <field name="exclusive" eval="0"/> <field name="sequence">50</field> </record> <record model="ir.module.category" id="module_category_administration"> <field name="name">Administration</field> <field name="sequence">100</field> </record> <record model="ir.module.category" id="module_category_usability"> <field name="name">Extra Rights</field> <field name="sequence">101</field> </record> <record model="ir.module.category" id="module_category_extra"> <field name="name">Other Extra Rights</field> <field name="sequence">102</field> </record>