diff --git a/icu4c/source/layoutex/layout/ParagraphLayout.h b/icu4c/source/layoutex/layout/ParagraphLayout.h
index 4efca1fb03e..d2dd824c18b 100644
--- a/icu4c/source/layoutex/layout/ParagraphLayout.h
+++ b/icu4c/source/layoutex/layout/ParagraphLayout.h
@@ -179,7 +179,7 @@ public:
 
         inline Line();
         inline Line(const Line &other);
-        inline Line &operator=(const Line & /*other*/) { return *this; };
+        inline Line &operator=(const Line & /*other*/) { return *this; }
 
         void computeMetrics();
 
@@ -342,7 +342,7 @@ public:
 
         inline VisualRun();
         inline VisualRun(const VisualRun &other);
-        inline VisualRun &operator=(const VisualRun &/*other*/) { return *this; };
+        inline VisualRun &operator=(const VisualRun &/*other*/) { return *this; }
 
         inline VisualRun(const LEFontInstance *font, UBiDiDirection direction, le_int32 glyphCount,
                   const LEGlyphID glyphs[], const float positions[], const le_int32 glyphToCharMap[]);
@@ -576,9 +576,9 @@ private:
           le_int32        glyphCount;
     };
 
-    ParagraphLayout() {};
-    ParagraphLayout(const ParagraphLayout & /*other*/) : UObject( ){};
-    inline ParagraphLayout &operator=(const ParagraphLayout & /*other*/) { return *this; };
+    ParagraphLayout() {}
+    ParagraphLayout(const ParagraphLayout & /*other*/) : UObject( ){}
+    inline ParagraphLayout &operator=(const ParagraphLayout & /*other*/) { return *this; }
 
     void computeLevels(UBiDiLevel paragraphLevel);
 
diff --git a/icu4c/source/layoutex/layout/RunArrays.h b/icu4c/source/layoutex/layout/RunArrays.h
index 69d57a0ebed..caf408abe92 100644
--- a/icu4c/source/layoutex/layout/RunArrays.h
+++ b/icu4c/source/layoutex/layout/RunArrays.h
@@ -214,7 +214,7 @@ private:
 
     inline RunArray();
     inline RunArray(const RunArray & /*other*/);
-    inline RunArray &operator=(const RunArray & /*other*/) { return *this; };
+    inline RunArray &operator=(const RunArray & /*other*/) { return *this; }
 
     const le_int32 *fLimits;
           le_int32  fCount;
@@ -371,7 +371,7 @@ private:
 
     inline FontRuns();
     inline FontRuns(const FontRuns &other);
-    inline FontRuns &operator=(const FontRuns & /*other*/) { return *this; };
+    inline FontRuns &operator=(const FontRuns & /*other*/) { return *this; }
 
     /**
      * The address of this static class variable serves as this class's ID
@@ -513,7 +513,7 @@ private:
 
     inline LocaleRuns();
     inline LocaleRuns(const LocaleRuns &other);
-    inline LocaleRuns &operator=(const LocaleRuns & /*other*/) { return *this; };
+    inline LocaleRuns &operator=(const LocaleRuns & /*other*/) { return *this; }
 
     /**
      * The address of this static class variable serves as this class's ID
@@ -645,7 +645,7 @@ private:
 
     inline ValueRuns();
     inline ValueRuns(const ValueRuns &other);
-    inline ValueRuns &operator=(const ValueRuns & /*other*/) { return *this; };
+    inline ValueRuns &operator=(const ValueRuns & /*other*/) { return *this; }
 
     /**
      * The address of this static class variable serves as this class's ID
diff --git a/icu4c/source/layoutex/plruns.cpp b/icu4c/source/layoutex/plruns.cpp
index 2bae89fb2bd..20346517dad 100644
--- a/icu4c/source/layoutex/plruns.cpp
+++ b/icu4c/source/layoutex/plruns.cpp
@@ -311,7 +311,7 @@ private:
 
     inline ULocRuns();
     inline ULocRuns(const ULocRuns &other);
-    inline ULocRuns &operator=(const ULocRuns & /*other*/) { return *this; };
+    inline ULocRuns &operator=(const ULocRuns & /*other*/) { return *this; }
     const char **fLocaleNames;
 };
 
diff --git a/icu4c/source/test/letest/cmaps.h b/icu4c/source/test/letest/cmaps.h
index f5580d0d84f..59653049569 100644
--- a/icu4c/source/test/letest/cmaps.h
+++ b/icu4c/source/test/letest/cmaps.h
@@ -27,7 +27,7 @@ public:
 protected:
     CMAPMapper(const CMAPTable *cmap);
 
-    CMAPMapper() {};
+    CMAPMapper() {}
 
 private:
     const CMAPTable *fcmap;
@@ -43,7 +43,7 @@ public:
     LEGlyphID unicodeToGlyph(LEUnicode32 unicode32) const override;
 
 protected:
-    CMAPFormat4Mapper() {};
+    CMAPFormat4Mapper() {}
 
 private:
     le_uint16       fEntrySelector;
@@ -64,7 +64,7 @@ public:
     LEGlyphID unicodeToGlyph(LEUnicode32 unicode32) const override;
 
 protected:
-    CMAPGroupMapper() {};
+    CMAPGroupMapper() {}
 
 private:
     le_int32 fPower;
diff --git a/icu4c/source/test/perf/collationperf/collperf.cpp b/icu4c/source/test/perf/collationperf/collperf.cpp
index c51f71c25a6..dfbd5099d54 100644
--- a/icu4c/source/test/perf/collationperf/collperf.cpp
+++ b/icu4c/source/test/perf/collationperf/collperf.cpp
@@ -1191,7 +1191,7 @@ void  UnixConvert() {
             exit(-1);
         }
         gFileLines[line].unixName[sizeNeeded] = 0;
-    };
+    }
     ucnv_close(cvrtr);
 }
 
@@ -1207,12 +1207,12 @@ public:
     UCharFile(const char *fileName);
     ~UCharFile();
     char16_t   get();
-    UBool   eof() {return fEof;};
-    UBool   error() {return fError;};
+    UBool   eof() {return fEof;}
+    UBool   error() {return fError;}
     
 private:
-    UCharFile (const UCharFile & /*other*/) {};                         // No copy constructor.
-    UCharFile & operator = (const UCharFile &/*other*/) {return *this;};   // No assignment op
+    UCharFile (const UCharFile & /*other*/) {}                         // No copy constructor.
+    UCharFile & operator = (const UCharFile &/*other*/) {return *this;}   // No assignment op
 
     FILE         *fFile;
     const char   *fName;
@@ -1352,7 +1352,7 @@ char16_t UCharFile::get() {
                 c = utf16Buf[0];
             }
             break;
-        };
+        }
     default:
         c = 0xFFFD; /* Error, unspecified codepage*/
         fprintf(stderr, "UCharFile: Error: unknown fEncoding\n");
diff --git a/icu4c/source/test/perf/leperf/cmaps.h b/icu4c/source/test/perf/leperf/cmaps.h
index e8f9e946d00..65c6c06cca8 100644
--- a/icu4c/source/test/perf/leperf/cmaps.h
+++ b/icu4c/source/test/perf/leperf/cmaps.h
@@ -31,7 +31,7 @@ public:
 protected:
     CMAPMapper(const CMAPTable *cmap);
 
-    CMAPMapper() {};
+    CMAPMapper() {}
 
 private:
     const CMAPTable *fcmap;
@@ -47,7 +47,7 @@ public:
     LEGlyphID unicodeToGlyph(LEUnicode32 unicode32) const override;
 
 protected:
-    CMAPFormat4Mapper() {};
+    CMAPFormat4Mapper() {}
 
 private:
     le_uint16       fEntrySelector;
@@ -68,7 +68,7 @@ public:
     LEGlyphID unicodeToGlyph(LEUnicode32 unicode32) const override;
 
 protected:
-    CMAPGroupMapper() {};
+    CMAPGroupMapper() {}
 
 private:
     le_int32 fPower;
diff --git a/icu4c/source/test/perf/ubrkperf/ubrkperf.h b/icu4c/source/test/perf/ubrkperf/ubrkperf.h
index 999769546d2..c11733d1473 100644
--- a/icu4c/source/test/perf/ubrkperf/ubrkperf.h
+++ b/icu4c/source/test/perf/ubrkperf/ubrkperf.h
@@ -109,7 +109,7 @@ public:
 
 class DarwinBreakFunction : public UPerfFunction {
 public:
-  void call(UErrorCode* status) override {};
+  void call(UErrorCode* status) override {}
 };
 
 class BreakIteratorPerformanceTest : public UPerfTest {