diff --git a/migrations/Version20251001132155.php b/migrations/Version20251001132155.php
new file mode 100644
index 0000000..30726b1
--- /dev/null
+++ b/migrations/Version20251001132155.php
@@ -0,0 +1,82 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+final class Version20251001132155 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Set and populate the `category` and `project_category` fields.';
+    }
+
+    public function up(Schema $schema): void
+    {
+        // this up() migration is auto-generated, please modify it to your needs
+        $this->addSql(<<<'SQL'
+            CREATE TABLE category (
+              id VARCHAR(255) NOT NULL,
+              PRIMARY KEY(id)
+            ) DEFAULT CHARACTER SET utf8mb4 COLLATE `utf8mb4_unicode_ci` ENGINE = InnoDB
+        SQL);
+        $this->addSql(<<<'SQL'
+            CREATE TABLE project_category (
+              project_id INT NOT NULL,
+              category_id VARCHAR(255) NOT NULL,
+              INDEX IDX_3B02921A166D1F9C (project_id),
+              INDEX IDX_3B02921A12469DE2 (category_id),
+              PRIMARY KEY(project_id, category_id)
+            ) DEFAULT CHARACTER SET utf8mb4 COLLATE `utf8mb4_unicode_ci` ENGINE = InnoDB
+        SQL);
+        $this->addSql(<<<'SQL'
+            ALTER TABLE
+              project_category
+            ADD
+              CONSTRAINT FK_3B02921A166D1F9C FOREIGN KEY (project_id) REFERENCES project (id) ON DELETE CASCADE
+        SQL);
+        $this->addSql(<<<'SQL'
+            ALTER TABLE
+              project_category
+            ADD
+              CONSTRAINT FK_3B02921A12469DE2 FOREIGN KEY (category_id) REFERENCES category (id) ON DELETE CASCADE
+        SQL);
+        $this->addSql(<<<'SQL'
+            ALTER TABLE project DROP category
+        SQL);
+
+        $this->addSql(<<<'SQL'
+            INSERT INTO category (id) VALUES ('education');
+            INSERT INTO category (id) VALUES ('culture');
+            INSERT INTO category (id) VALUES ('journalism');
+            INSERT INTO category (id) VALUES ('democracy');
+            INSERT INTO category (id) VALUES ('rural-development');
+            INSERT INTO category (id) VALUES ('health-and-cares');
+            INSERT INTO category (id) VALUES ('science-and-technology');
+            INSERT INTO category (id) VALUES ('sustainability');
+            INSERT INTO category (id) VALUES ('social-economy');
+        SQL);
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql(<<<'SQL'
+            ALTER TABLE project_category DROP FOREIGN KEY FK_3B02921A166D1F9C
+        SQL);
+        $this->addSql(<<<'SQL'
+            ALTER TABLE project_category DROP FOREIGN KEY FK_3B02921A12469DE2
+        SQL);
+        $this->addSql(<<<'SQL'
+            DROP TABLE category
+        SQL);
+        $this->addSql(<<<'SQL'
+            DROP TABLE project_category
+        SQL);
+        $this->addSql(<<<'SQL'
+            ALTER TABLE project ADD category VARCHAR(255) NOT NULL
+        SQL);
+    }
+}
diff --git a/src/ApiResource/Project/ProjectApiResource.php b/src/ApiResource/Project/ProjectApiResource.php
index af64ffb..bf0b121 100644
--- a/src/ApiResource/Project/ProjectApiResource.php
+++ b/src/ApiResource/Project/ProjectApiResource.php
@@ -13,7 +13,6 @@ use App\Dto\ProjectCreationDto;
 use App\Dto\ProjectUpdationDto;
 use App\Entity\Project\Project;
 use App\Entity\Project\ProjectCalendar;
-use App\Entity\Project\ProjectCategory;
 use App\Entity\Project\ProjectDeadline;
 use App\Entity\Project\ProjectStatus;
 use App\Entity\Project\ProjectVideo;
@@ -109,11 +108,11 @@ class ProjectApiResource
     public ProjectCalendar $calendar;
 
     /**
-     * One of the available categories.
+     * A list of the available categories most relevant to this Project.
      */
     #[Assert\NotBlank()]
     #[API\ApiFilter(filterClass: SearchFilter::class, strategy: 'exact')]
-    public ProjectCategory $category;
+    public array $categories;
 
     /**
      * ISO 3166 data about the Project's territory of interest.
diff --git a/src/Entity/Category.php b/src/Entity/Category.php
new file mode 100644
index 0000000..7227ca8
--- /dev/null
+++ b/src/Entity/Category.php
@@ -0,0 +1,19 @@
+<?php
+
+namespace App\Entity;
+
+use App\Repository\CategoryRepository;
+use Doctrine\ORM\Mapping as ORM;
+
+#[ORM\Entity(repositoryClass: CategoryRepository::class)]
+class Category
+{
+    #[ORM\Id]
+    #[ORM\Column(length: 255)]
+    private ?string $id = null;
+
+    public function getId(): ?string
+    {
+        return $this->id;
+    }
+}
diff --git a/src/Entity/Project/Project.php b/src/Entity/Project/Project.php
index a34b5dc..8d73307 100644
--- a/src/Entity/Project/Project.php
+++ b/src/Entity/Project/Project.php
@@ -3,6 +3,7 @@
 namespace App\Entity\Project;
 
 use App\Entity\Accounting\Accounting;
+use App\Entity\Category;
 use App\Entity\Interface\AccountingOwnerInterface;
 use App\Entity\Interface\LocalizedEntityInterface;
 use App\Entity\Interface\UserOwnedInterface;
@@ -64,8 +65,11 @@ class Project implements UserOwnedInterface, AccountingOwnerInterface, Localized
     #[ORM\Embedded(class: ProjectCalendar::class)]
     private ?ProjectCalendar $calendar = null;
 
-    #[ORM\Column(enumType: ProjectCategory::class)]
-    private ?ProjectCategory $category = null;
+    /**
+     * @var Collection<int, Category>
+     */
+    #[ORM\ManyToMany(targetEntity: Category::class)]
+    private Collection $categories;
 
     /**
      * Project's territory of interest.
@@ -145,6 +149,7 @@ class Project implements UserOwnedInterface, AccountingOwnerInterface, Localized
         $this->budgetItems = new ArrayCollection();
         $this->updates = new ArrayCollection();
         $this->supports = new ArrayCollection();
+        $this->categories = new ArrayCollection();
     }
 
     public function getId(): ?int
@@ -219,14 +224,26 @@ class Project implements UserOwnedInterface, AccountingOwnerInterface, Localized
         return $this;
     }
 
-    public function getCategory(): ?ProjectCategory
+    /**
+     * @return Collection<int, Category>
+     */
+    public function getCategories(): Collection
     {
-        return $this->category;
+        return $this->categories;
     }
 
-    public function setCategory(ProjectCategory $category): static
+    public function addCategory(Category $category): static
     {
-        $this->category = $category;
+        if (!$this->categories->contains($category)) {
+            $this->categories->add($category);
+        }
+
+        return $this;
+    }
+
+    public function removeCategory(Category $category): static
+    {
+        $this->categories->removeElement($category);
 
         return $this;
     }
diff --git a/src/Repository/CategoryRepository.php b/src/Repository/CategoryRepository.php
new file mode 100644
index 0000000..2ea6ad9
--- /dev/null
+++ b/src/Repository/CategoryRepository.php
@@ -0,0 +1,43 @@
+<?php
+
+namespace App\Repository;
+
+use App\Entity\Category;
+use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
+use Doctrine\Persistence\ManagerRegistry;
+
+/**
+ * @extends ServiceEntityRepository<Category>
+ */
+class CategoryRepository extends ServiceEntityRepository
+{
+    public function __construct(ManagerRegistry $registry)
+    {
+        parent::__construct($registry, Category::class);
+    }
+
+    //    /**
+    //     * @return Category[] Returns an array of Category objects
+    //     */
+    //    public function findByExampleField($value): array
+    //    {
+    //        return $this->createQueryBuilder('c')
+    //            ->andWhere('c.exampleField = :val')
+    //            ->setParameter('val', $value)
+    //            ->orderBy('c.id', 'ASC')
+    //            ->setMaxResults(10)
+    //            ->getQuery()
+    //            ->getResult()
+    //        ;
+    //    }
+
+    //    public function findOneBySomeField($value): ?Category
+    //    {
+    //        return $this->createQueryBuilder('c')
+    //            ->andWhere('c.exampleField = :val')
+    //            ->setParameter('val', $value)
+    //            ->getQuery()
+    //            ->getOneOrNullResult()
+    //        ;
+    //    }
+}