diff --git a/beachball.config.js b/beachball.config.js
index e9d8650a3..45411dd73 100644
--- a/beachball.config.js
+++ b/beachball.config.js
@@ -4,6 +4,7 @@
 // TODO: fix this type ("commit" should be allowed in repo options)
 /** @type {BeachballConfig & Partial<CliOptions>}*/
 const config = {
+  generateChangelog: true,
   ignorePatterns: [
     '.*',
     '.*/**',
diff --git a/change/beachball-5d5354cf-7fea-4291-8be7-1aee3118125e.json b/change/beachball-5d5354cf-7fea-4291-8be7-1aee3118125e.json
new file mode 100644
index 000000000..7608ab420
--- /dev/null
+++ b/change/beachball-5d5354cf-7fea-4291-8be7-1aee3118125e.json
@@ -0,0 +1,7 @@
+{
+  "type": "major",
+  "comment": "[BREAKING] Set `generateChangelog` to `'md'` by default (only write `CHANGELOG.md`, not `CHANGELOG.json`). To keep the old behavior, set `generateChangelog: true`. Or if you're not using the `CHANGELOG.json` files, it's safe to delete them.' (See #978 and #979 for more context.)",
+  "packageName": "beachball",
+  "email": "elcraig@microsoft.com",
+  "dependentChangeType": "patch"
+}
diff --git a/src/__functional__/changelog/__snapshots__/writeChangelog.test.ts.snap b/src/__functional__/changelog/__snapshots__/writeChangelog.test.ts.snap
index 4435f9d3c..8bf195476 100644
--- a/src/__functional__/changelog/__snapshots__/writeChangelog.test.ts.snap
+++ b/src/__functional__/changelog/__snapshots__/writeChangelog.test.ts.snap
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`writeChangelog generates basic changelog: changelog md 1`] = `
+exports[`writeChangelog generates basic changelog (md only by default): changelog md 1`] = `
 "# Change Log - foo
 
 <!-- This log was last generated on (date) and should not be manually modified. -->
diff --git a/src/__functional__/changelog/writeChangelog.test.ts b/src/__functional__/changelog/writeChangelog.test.ts
index d23bcc344..e93cbd9f6 100644
--- a/src/__functional__/changelog/writeChangelog.test.ts
+++ b/src/__functional__/changelog/writeChangelog.test.ts
@@ -110,7 +110,7 @@ describe('writeChangelog', () => {
     expect(readChangelogJson(repo.rootPath)).toBeNull();
   });
 
-  it('generates basic changelog', async () => {
+  it('generates basic changelog (md only by default)', async () => {
     repo = sharedSingleRepo;
     const options = getOptions();
 
@@ -129,6 +129,25 @@ describe('writeChangelog', () => {
     expect(changelogMd).not.toContain('no comment');
     expect(changelogMd).toMatchSnapshot('changelog md');
 
+    const changelogJson = readChangelogJson(repo.rootPath);
+    expect(changelogJson).toBeNull();
+  });
+
+  it('generates basic changelog md and json if generateChangelog is true', async () => {
+    repo = sharedSingleRepo;
+    const options = getOptions({ generateChangelog: true });
+
+    generateChangeFiles([getChange('foo', 'old minor comment')], options);
+    generateChangeFiles([getChange('foo', 'patch comment', 'patch')], options);
+    generateChangeFiles([getChange('foo', 'no comment', 'none')], options);
+    generateChangeFiles([getChange('foo', 'new minor comment', 'minor')], options);
+
+    await writeChangelogWrapper({ options });
+
+    const changelogMd = readChangelogMd(repo.rootPath);
+    // Just verify that this one was written (prevoius test covered details)
+    expect(changelogMd).toMatch(/^# Change Log - foo/);
+
     const changelogJson = readChangelogJson(repo.rootPath);
     expect(changelogJson).toEqual({ name: 'foo', entries: [expect.anything()] });
     expect(changelogJson!.entries[0]).toEqual({
@@ -173,7 +192,7 @@ describe('writeChangelog', () => {
 
   it('generates changelogs with dependent changes in monorepo', async () => {
     repo = sharedMonoRepo;
-    const options = getOptions();
+    const options = getOptions({ generateChangelog: true });
 
     generateChangeFiles([{ packageName: 'foo', comment: 'foo comment' }], options);
     generateChangeFiles([{ packageName: 'baz', comment: 'baz comment' }], options);
@@ -242,7 +261,7 @@ describe('writeChangelog', () => {
 
   it('generates changelog in monorepo with grouped change files (groupChanges)', async () => {
     repo = sharedMonoRepo;
-    const options = getOptions({ groupChanges: true });
+    const options = getOptions({ groupChanges: true, generateChangelog: true });
 
     // these will be in one change file
     generateChangeFiles([getChange('foo', 'comment 2'), getChange('bar', 'bar comment')], options);
@@ -280,6 +299,7 @@ describe('writeChangelog', () => {
   it('generates grouped changelog in monorepo', async () => {
     repo = sharedMonoRepo;
     const options = getOptions({
+      generateChangelog: true,
       changelog: {
         groups: [
           {
@@ -351,6 +371,7 @@ describe('writeChangelog', () => {
   it('generates grouped changelog when path overlaps with regular changelog', async () => {
     repo = sharedMonoRepo;
     const options = getOptions({
+      generateChangelog: true,
       changelog: {
         groups: [
           {
@@ -497,7 +518,7 @@ describe('writeChangelog', () => {
     // Most of the previous content tests are handled by renderChangelog, but writeChangelog is
     // responsible for reading that content and passing it in.
     repo = sharedSingleRepo;
-    const options = getOptions();
+    const options = getOptions({ generateChangelog: true });
 
     // Write some changes and generate changelogs
     generateChangeFiles(['foo'], options);
@@ -528,7 +549,7 @@ describe('writeChangelog', () => {
 
   it('appends to existing changelog when migrating from uniqueFilenames=false to true', async () => {
     repo = sharedSingleRepo;
-    const options = getOptions();
+    const options = getOptions({ generateChangelog: true });
 
     // Write some changes and generate changelogs
     generateChangeFiles(['foo'], options);
@@ -566,7 +587,10 @@ describe('writeChangelog', () => {
 
   it('trims previous changelog entries over maxVersions', async () => {
     repo = sharedSingleRepo;
-    const options = getOptions({ changelog: { maxVersions: 2 } });
+    const options = getOptions({
+      generateChangelog: true,
+      changelog: { maxVersions: 2 },
+    });
 
     // Bump and write three times
     for (let i = 1; i <= 3; i++) {
diff --git a/src/options/getDefaultOptions.ts b/src/options/getDefaultOptions.ts
index 8d100198d..0421396cf 100644
--- a/src/options/getDefaultOptions.ts
+++ b/src/options/getDefaultOptions.ts
@@ -22,7 +22,7 @@ export function getDefaultOptions(): BeachballOptions {
     depth: undefined,
     disallowedChangeTypes: null,
     fetch: true,
-    generateChangelog: true,
+    generateChangelog: 'md',
     gitTags: true,
     gitTimeout: undefined,
     message: '',
diff --git a/src/types/BeachballOptions.ts b/src/types/BeachballOptions.ts
index 9dd4dd6e8..216a017b2 100644
--- a/src/types/BeachballOptions.ts
+++ b/src/types/BeachballOptions.ts
@@ -112,10 +112,11 @@ export interface RepoOptions {
   fetch: boolean;
   /**
    * Whether to generate changelog files.
-   * - `true` (default) to generate both CHANGELOG.md and CHANGELOG.json
+   * - `'md'` (default) to generate only CHANGELOG.md
+   * - `true` to generate both CHANGELOG.md and CHANGELOG.json
    * - `false` to skip changelog generation
-   * - `'md'` to generate only CHANGELOG.md
    * - `'json'` to generate only CHANGELOG.json
+   * @default 'md'
    */
   generateChangelog: boolean | 'md' | 'json';
   /** Options for bumping package versions together */