diff --git a/core/modules/filters/strings.js b/core/modules/filters/strings.js
index d844f7c56..d2a9b5f0b 100644
--- a/core/modules/filters/strings.js
+++ b/core/modules/filters/strings.js
@@ -26,6 +26,10 @@ exports.lowercase = makeStringBinaryOperator(
 	function(a) {return [("" + a).toLowerCase()];}
 );
 
+exports.sentencecase = makeStringBinaryOperator(
+	function(a) {return [$tw.utils.toSentenceCase(a)];}
+);
+
 exports.trim = makeStringBinaryOperator(
 	function(a) {return [$tw.utils.trim(a)];}
 );
diff --git a/core/modules/utils/utils.js b/core/modules/utils/utils.js
index 672961a40..1b1ccb548 100644
--- a/core/modules/utils/utils.js
+++ b/core/modules/utils/utils.js
@@ -92,6 +92,13 @@ exports.trim = function(str) {
 	}
 };
 
+/*
+Convert a string to sentence case (ie capitalise each initial letter)
+*/
+exports.toSentenceCase = function(str) {
+  return (str || "").toLowerCase().replace(/(^|\s)\S/g, function(c) {return c.toUpperCase();});
+}
+
 /*
 Find the line break preceding a given position in a string
 Returns position immediately after that line break, or the start of the string
diff --git a/editions/prerelease/tiddlers/Release 5.1.20.tid b/editions/prerelease/tiddlers/Release 5.1.20.tid
index d33006329..c1e52d6b2 100644
--- a/editions/prerelease/tiddlers/Release 5.1.20.tid	
+++ b/editions/prerelease/tiddlers/Release 5.1.20.tid	
@@ -11,7 +11,7 @@ type: text/vnd.tiddlywiki
 
 Added several new [[Mathematics Operators]] for working with numbers: [[negate|negate Operator]], [[abs|abs Operator]], [[ceil|ceil Operator]], [[floor|floor Operator]], [[round|round Operator]], [[trunc|trunc Operator]], [[untrunc|untrunc Operator]], [[sign|sign Operator]], [[add|add Operator]], [[subtract|subtract Operator]], [[multiply|multiply Operator]], [[divide|divide Operator]], [[remainder|remainder Operator]], [[max|max Operator]], [[min|min Operator]], [[fixed|fixed Operator]], [[precision|precision Operator]], [[exponential|exponential Operator]], [[sum|sum Operator]], [[product|product Operator]], [[maxall|maxall Operator]] and [[minall|minall Operator]].
 
-Added several new string operators: [[length|length Operator]], [[uppercase|uppercase Operator]], [[lowercase|lowercase Operator]], [[trim|trim Operator]], [[split|split Operator]], [[splitregexp|splitregexp Operator]] and [[join|join Operator]].
+Added several new string operators: [[length|length Operator]], [[uppercase|uppercase Operator]], [[lowercase|lowercase Operator]], [[sentencecase|sentencecase Operator]], [[trim|trim Operator]], [[split|split Operator]], [[splitregexp|splitregexp Operator]] and [[join|join Operator]].
 
 There is now finer control over TiddlyWiki's default behaviour of removing duplicates from filter results, making it much easier to work with the new mathematics and string operators:
 
diff --git a/editions/tw5.com/tiddlers/filters/examples/sentencecase Operator (Examples).tid b/editions/tw5.com/tiddlers/filters/examples/sentencecase Operator (Examples).tid
new file mode 100644
index 000000000..5dd2a26bc
--- /dev/null
+++ b/editions/tw5.com/tiddlers/filters/examples/sentencecase Operator (Examples).tid	
@@ -0,0 +1,8 @@
+created: 20190619110741485
+modified: 20190619110812080
+tags: [[uppercase Operator]] [[Operator Examples]]
+title: sentencecase Operator (Examples)
+type: text/vnd.tiddlywiki
+
+<<.operator-example 1 "[[abc def ghi jkl]sentencecase[]]">>
+<<.operator-example 2 "[tag[HelloThere]sentencecase[]]">>
diff --git a/editions/tw5.com/tiddlers/filters/lowercase Operator.tid b/editions/tw5.com/tiddlers/filters/lowercase Operator.tid
index 1efaec980..110c79345 100644
--- a/editions/tw5.com/tiddlers/filters/lowercase Operator.tid	
+++ b/editions/tw5.com/tiddlers/filters/lowercase Operator.tid	
@@ -1,6 +1,6 @@
 caption: lowercase
 created: 20190613153650010
-modified: 20190613153726427
+modified: 20190619110848522
 op-input: a [[selection of titles|Title Selection]]
 op-output: the input titles with each uppercase letter replaced by the equivalent lowercase letter
 op-purpose: returns each item in the list as lowercase
@@ -10,6 +10,6 @@ type: text/vnd.tiddlywiki
 
 <<.from-version "5.1.20">>
 
-See also [[uppercase Operator]].
+See also [[uppercase Operator]] and [[sentencecase Operator]].
 
 <<.operator-examples "lowercase">>
diff --git a/editions/tw5.com/tiddlers/filters/sentencecase Operator.tid b/editions/tw5.com/tiddlers/filters/sentencecase Operator.tid
new file mode 100644
index 000000000..dc2262ee2
--- /dev/null
+++ b/editions/tw5.com/tiddlers/filters/sentencecase Operator.tid	
@@ -0,0 +1,15 @@
+caption: sentencecase
+created: 20190619110607457
+modified: 20190619110736016
+op-input: a [[selection of titles|Title Selection]]
+op-output: the input titles with each word capitalised
+op-purpose: returns each item in the list capitalised
+tags: [[Filter Operators]]
+title: sentencecase Operator
+type: text/vnd.tiddlywiki
+
+<<.from-version "5.1.20">>
+
+See also [[lowercase Operator]], [[uppercase Operator]].
+
+<<.operator-examples "sentencecase">>
diff --git a/editions/tw5.com/tiddlers/filters/uppercase Operator.tid b/editions/tw5.com/tiddlers/filters/uppercase Operator.tid
index f52031bee..192922a3c 100644
--- a/editions/tw5.com/tiddlers/filters/uppercase Operator.tid	
+++ b/editions/tw5.com/tiddlers/filters/uppercase Operator.tid	
@@ -1,6 +1,6 @@
 caption: uppercase
 created: 20190613153420821
-modified: 20190613153538557
+modified: 20190619110837473
 op-input: a [[selection of titles|Title Selection]]
 op-output: the input titles with each lowercase letter replaced by the equivalent uppercase letter
 op-purpose: returns each item in the list as uppercase
@@ -10,6 +10,6 @@ type: text/vnd.tiddlywiki
 
 <<.from-version "5.1.20">>
 
-See also [[lowercase Operator]].
+See also [[lowercase Operator]] and [[sentencecase Operator]].
 
 <<.operator-examples "uppercase">>