diff --git a/client/src/components/campaign/OpenDisputeForm.tsx b/client/src/components/campaign/OpenDisputeForm.tsx
new file mode 100644
index 0000000..a684839
--- /dev/null
+++ b/client/src/components/campaign/OpenDisputeForm.tsx
@@ -0,0 +1,145 @@
+import { useState } from 'react';
+import type { FormEvent } from 'react';
+import { useWallet } from '../../context/WalletContext';
+import {
+  useContribution,
+  useDispute,
+  useEscrowAdmin,
+  useOpenDispute,
+} from '../../hooks/contract';
+import { toUserFacingError } from '../../lib/soroban/userFacingError';
+
+const cardClass =
+  'rounded-campaign border border-soil-200 bg-white p-6 shadow-campaign';
+const primaryButtonClass =
+  'inline-flex items-center justify-center rounded-lg bg-leaf-700 px-4 py-2 text-sm font-semibold text-white transition-colors hover:bg-leaf-800 focus:outline-none focus-visible:ring-2 focus-visible:ring-leaf-500 focus-visible:ring-offset-2 disabled:cursor-not-allowed disabled:opacity-50';
+const inputClass =
+  'w-full rounded-lg border border-soil-300 px-3 py-2 text-body-sm text-soil-900 focus:border-leaf-500 focus:outline-none focus:ring-1 focus:ring-leaf-500';
+const labelClass = 'mb-1 block text-label text-soil-500';
+const errorClass = 'mt-1 text-caption text-status-failed-dark';
+const sectionTitleClass = 'text-h4 text-soil-900';
+
+function ActionError({ message }: { message: string | null }) {
+  if (!message) return null;
+  return <p className={errorClass}>{message}</p>;
+}
+
+export interface OpenDisputeFormProps {
+  campaignId: string;
+  farmerAddress: string;
+}
+
+/**
+ * Lets a campaign's farmer, a contributing investor, or the escrow admin
+ * open a dispute. Eligibility is a UX convenience only — `open_dispute`
+ * enforces the same set on-chain via `.require_auth()`.
+ */
+export function OpenDisputeForm({
+  campaignId,
+  farmerAddress,
+}: OpenDisputeFormProps) {
+  const { publicKey } = useWallet();
+  const openDispute = useOpenDispute();
+  const { data: contribution } = useContribution(
+    campaignId,
+    publicKey ?? undefined,
+  );
+  const { data: adminAddress } = useEscrowAdmin();
+  const { data: dispute } = useDispute(campaignId);
+
+  const [reason, setReason] = useState('');
+  const [formError, setFormError] = useState<string | null>(null);
+  const [success, setSuccess] = useState(false);
+
+  const hasOpenDispute = dispute?.status?.tag === 'Open';
+
+  if (!publicKey) {
+    return (
+      <div className={cardClass}>
+        <h3 className={sectionTitleClass}>Open a dispute</h3>
+        <p className="mt-2 text-body-sm text-soil-500">
+          Connect your wallet to open a dispute on this campaign.
+        </p>
+      </div>
+    );
+  }
+
+  const isFarmer = publicKey === farmerAddress;
+  const isContributor = (contribution ?? 0n) > 0n;
+  const isAdmin = publicKey === adminAddress;
+  const canOpenDispute = isFarmer || isContributor || isAdmin;
+
+  if (!canOpenDispute) return null;
+
+  if (hasOpenDispute) {
+    return (
+      <div className={cardClass}>
+        <h3 className={sectionTitleClass}>Open a dispute</h3>
+        <p className="mt-2 text-body-sm text-soil-500" role="status">
+          A dispute is already open on this campaign — an admin needs to resolve
+          it before a new one can be opened.
+        </p>
+      </div>
+    );
+  }
+
+  async function handleSubmit(event: FormEvent) {
+    event.preventDefault();
+    setFormError(null);
+    setSuccess(false);
+
+    if (reason.trim().length === 0) {
+      setFormError('Enter a reason for the dispute.');
+      return;
+    }
+
+    try {
+      await openDispute.mutateAsync({
+        campaignId,
+        opener: publicKey!,
+        reason: reason.trim(),
+      });
+      setSuccess(true);
+      setReason('');
+    } catch (err) {
+      setFormError(toUserFacingError(err));
+    }
+  }
+
+  return (
+    <div className={cardClass}>
+      <form onSubmit={handleSubmit} className="space-y-3">
+        <h3 className={sectionTitleClass}>Open a dispute</h3>
+        <p className="text-body-sm text-soil-500">
+          Raising a dispute pauses fund releases until an admin resolves it.
+        </p>
+        <div>
+          <label className={labelClass} htmlFor="dispute-reason">
+            Reason
+          </label>
+          <textarea
+            id="dispute-reason"
+            className={inputClass}
+            rows={3}
+            value={reason}
+            onChange={(e) => setReason(e.target.value)}
+            placeholder="Describe why you're opening this dispute…"
+          />
+        </div>
+        <button
+          type="submit"
+          disabled={openDispute.isPending}
+          className={primaryButtonClass}
+        >
+          {openDispute.isPending ? 'Confirm in wallet…' : 'Open dispute'}
+        </button>
+        <ActionError message={formError} />
+        {success && (
+          <p className="text-caption text-status-active-dark">
+            Dispute opened.
+          </p>
+        )}
+      </form>
+    </div>
+  );
+}
diff --git a/client/src/components/campaign/__tests__/OpenDisputeForm.test.tsx b/client/src/components/campaign/__tests__/OpenDisputeForm.test.tsx
new file mode 100644
index 0000000..4c3276f
--- /dev/null
+++ b/client/src/components/campaign/__tests__/OpenDisputeForm.test.tsx
@@ -0,0 +1,159 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import { OpenDisputeForm } from '../OpenDisputeForm';
+import type { Dispute } from '../../../lib/soroban/types';
+
+const FARMER = 'GFARMER0000000000000000000000000000000000000000000000000';
+const CONTRIBUTOR = 'GINVESTOR000000000000000000000000000000000000000000000';
+const ADMIN = 'GADMIN00000000000000000000000000000000000000000000000000';
+const STRANGER = 'GSTRANGER00000000000000000000000000000000000000000000000';
+
+const mockOpenDispute = vi.fn();
+let mockPublicKey: string | null = FARMER;
+let mockContribution = 0n;
+let mockAdmin: string | undefined = ADMIN;
+let mockDispute: Dispute | undefined;
+
+vi.mock('../../../context/WalletContext', () => ({
+  useWallet: () => ({ publicKey: mockPublicKey }),
+}));
+
+vi.mock('../../../hooks/contract', () => ({
+  useOpenDispute: () => ({ mutateAsync: mockOpenDispute, isPending: false }),
+  useContribution: () => ({ data: mockContribution }),
+  useEscrowAdmin: () => ({ data: mockAdmin }),
+  useDispute: () => ({ data: mockDispute }),
+}));
+
+beforeEach(() => {
+  mockOpenDispute.mockReset();
+  mockPublicKey = FARMER;
+  mockContribution = 0n;
+  mockAdmin = ADMIN;
+  mockDispute = undefined;
+});
+
+describe('OpenDisputeForm', () => {
+  it('prompts to connect a wallet when none is connected', () => {
+    mockPublicKey = null;
+    render(<OpenDisputeForm campaignId="42" farmerAddress={FARMER} />);
+
+    expect(
+      screen.getByText(/connect your wallet to open a dispute/i),
+    ).toBeInTheDocument();
+    expect(screen.queryByRole('button', { name: /open dispute/i })).toBeNull();
+  });
+
+  it('renders nothing for a connected wallet that is not the farmer, a contributor, or the admin', () => {
+    mockPublicKey = STRANGER;
+    mockContribution = 0n;
+    const { container } = render(
+      <OpenDisputeForm campaignId="42" farmerAddress={FARMER} />,
+    );
+
+    expect(container).toBeEmptyDOMElement();
+  });
+
+  it('lets the farmer open a dispute', async () => {
+    mockPublicKey = FARMER;
+    const user = userEvent.setup();
+    render(<OpenDisputeForm campaignId="42" farmerAddress={FARMER} />);
+
+    await user.type(
+      screen.getByLabelText(/reason/i),
+      'Harvest outcome does not match the report.',
+    );
+    await user.click(screen.getByRole('button', { name: /open dispute/i }));
+
+    expect(mockOpenDispute).toHaveBeenCalledWith({
+      campaignId: '42',
+      opener: FARMER,
+      reason: 'Harvest outcome does not match the report.',
+    });
+    expect(await screen.findByText(/dispute opened/i)).toBeInTheDocument();
+  });
+
+  it('lets a contributing investor open a dispute', async () => {
+    mockPublicKey = CONTRIBUTOR;
+    mockContribution = 500n;
+    const user = userEvent.setup();
+    render(<OpenDisputeForm campaignId="42" farmerAddress={FARMER} />);
+
+    await user.type(screen.getByLabelText(/reason/i), 'Funds not released.');
+    await user.click(screen.getByRole('button', { name: /open dispute/i }));
+
+    expect(mockOpenDispute).toHaveBeenCalledWith({
+      campaignId: '42',
+      opener: CONTRIBUTOR,
+      reason: 'Funds not released.',
+    });
+  });
+
+  it('lets the admin open a dispute', async () => {
+    mockPublicKey = ADMIN;
+    mockContribution = 0n;
+    const user = userEvent.setup();
+    render(<OpenDisputeForm campaignId="42" farmerAddress={FARMER} />);
+
+    await user.type(
+      screen.getByLabelText(/reason/i),
+      'Investigating on behalf of a reporter.',
+    );
+    await user.click(screen.getByRole('button', { name: /open dispute/i }));
+
+    expect(mockOpenDispute).toHaveBeenCalledTimes(1);
+  });
+
+  it('rejects an empty reason client-side and does not call the mutation', async () => {
+    const user = userEvent.setup();
+    render(<OpenDisputeForm campaignId="42" farmerAddress={FARMER} />);
+
+    await user.click(screen.getByRole('button', { name: /open dispute/i }));
+
+    expect(
+      await screen.findByText(/enter a reason for the dispute/i),
+    ).toBeInTheDocument();
+    expect(mockOpenDispute).not.toHaveBeenCalled();
+  });
+
+  it('surfaces a contract-level rejection as a readable error without clearing the form', async () => {
+    mockOpenDispute.mockRejectedValueOnce(
+      new Error(
+        'HostError: Error(Contract, #7)\nlong diagnostic dump that should be truncated',
+      ),
+    );
+    const user = userEvent.setup();
+    render(<OpenDisputeForm campaignId="42" farmerAddress={FARMER} />);
+
+    const reasonInput = screen.getByLabelText(/reason/i);
+    await user.type(reasonInput, 'Disputing harvest outcome.');
+    await user.click(screen.getByRole('button', { name: /open dispute/i }));
+
+    expect(
+      await screen.findByText(/HostError: Error\(Contract, #7\)/),
+    ).toBeInTheDocument();
+    expect(reasonInput).toHaveValue('Disputing harvest outcome.');
+  });
+
+  it('does not render the open-dispute form when a dispute is already Open', () => {
+    mockDispute = {
+      campaign_id: 42n,
+      opener: FARMER,
+      reason: 'Harvest_delay',
+      timestamp: 0n,
+      ledger_sequence: 0,
+      status: { tag: 'Open' },
+      resolution: { tag: 'Pending' },
+    };
+    render(<OpenDisputeForm campaignId="42" farmerAddress={FARMER} />);
+
+    expect(
+      screen.getByText(
+        /a dispute is already open on this campaign — an admin needs to resolve it/i,
+      ),
+    ).toBeInTheDocument();
+    expect(screen.queryByLabelText(/reason/i)).toBeNull();
+    expect(screen.queryByRole('button', { name: /open dispute/i })).toBeNull();
+  });
+});
diff --git a/client/src/pages/CampaignDetailPage.tsx b/client/src/pages/CampaignDetailPage.tsx
index bcc8407..d2479a5 100644
--- a/client/src/pages/CampaignDetailPage.tsx
+++ b/client/src/pages/CampaignDetailPage.tsx
@@ -2,6 +2,7 @@ import React, { useState } from 'react';
 import { FundCampaignModal } from '../components/campaign/FundCampaignModal';
 import { StatusBadge } from '../components/campaign/StatusBadge';
 import { ActivityFeed } from '../components/campaign/ActivityFeed';
+import { OpenDisputeForm } from '../components/campaign/OpenDisputeForm';
 import { useCampaignLiveUpdates } from '../hooks/useCampaignLiveUpdates';
 import { DetailPageSkeleton } from '../components/ui/Skeleton/Skeleton';
 
@@ -12,6 +13,7 @@ export interface CampaignData {
   totalTarget: number;
   currentRaised: number;
   status: 'Active' | 'Funding' | 'Resolved' | 'Failed' | 'Settled';
+  farmer: string;
 }
 
 export const CampaignDetailPage: React.FC = () => {
@@ -28,6 +30,8 @@ export const CampaignDetailPage: React.FC = () => {
         totalTarget: 50000,
         currentRaised: 32500,
         status: 'Funding',
+        farmer:
+          'GDF4X5Y6Z7A8B9C0D1E2F3G4H5I6J7K8L9M0N1O2P3Q4R5S6T7U8V9W0X1Y2Z3',
       });
     }, 0);
     return () => window.clearTimeout(timer);
@@ -137,6 +141,11 @@ export const CampaignDetailPage: React.FC = () => {
           refreshIntervalMs={30_000}
         />
       </div>
+
+      <OpenDisputeForm
+        campaignId={campaign.id}
+        farmerAddress={campaign.farmer}
+      />
     </div>
   );
 };