diff --git a/changelog/change_upgrade_regexp_parser_to_20.md b/changelog/change_upgrade_regexp_parser_to_20.md
new file mode 100644
index 00000000000..feda3fde7fe
--- /dev/null
+++ b/changelog/change_upgrade_regexp_parser_to_20.md
@@ -0,0 +1 @@
+* [#9102](https://github.com/rubocop-hq/rubocop/pull/9102): Upgrade regexp_parser to 2.0. ([@knu][])
diff --git a/lib/rubocop/cop/style/redundant_regexp_escape.rb b/lib/rubocop/cop/style/redundant_regexp_escape.rb
index cabdd14a407..4f13913d6ca 100644
--- a/lib/rubocop/cop/style/redundant_regexp_escape.rb
+++ b/lib/rubocop/cop/style/redundant_regexp_escape.rb
@@ -82,7 +82,7 @@ def delimiter?(node, char)
 
         def each_escape(node)
           node.parsed_tree&.traverse&.reduce(0) do |char_class_depth, (event, expr)|
-            yield(expr.text[1], expr.start_index, !char_class_depth.zero?) if expr.type == :escape
+            yield(expr.text[1], expr.ts, !char_class_depth.zero?) if expr.type == :escape
 
             if expr.type == :set
               char_class_depth + (event == :enter ? 1 : -1)
diff --git a/lib/rubocop/ext/regexp_node.rb b/lib/rubocop/ext/regexp_node.rb
index 9a2591c0aaf..adbf67437f5 100644
--- a/lib/rubocop/ext/regexp_node.rb
+++ b/lib/rubocop/ext/regexp_node.rb
@@ -19,18 +19,13 @@ def assign_properties(*)
         super
 
         str = with_interpolations_blanked
-        begin
-          @parsed_tree = Regexp::Parser.parse(str, options: options)
+        @parsed_tree = begin
+          Regexp::Parser.parse(str, options: options)
         rescue StandardError
-          @parsed_tree = nil
-        else
-          origin = loc.begin.end
-          source = @parsed_tree.to_s
-          @parsed_tree.each_expression(true) do |e|
-            e.origin = origin
-            e.source = source
-          end
+          nil
         end
+        origin = loc.begin.end
+        @parsed_tree&.each_expression(true) { |e| e.origin = origin }
       end
 
       def each_capture(named: ANY)
diff --git a/lib/rubocop/ext/regexp_parser.rb b/lib/rubocop/ext/regexp_parser.rb
index 91e8fefe2c0..87df5f1832c 100644
--- a/lib/rubocop/ext/regexp_parser.rb
+++ b/lib/rubocop/ext/regexp_parser.rb
@@ -20,18 +20,11 @@ def initialize(expression, body:, quantifier: nil, begin_l: nil, end_l: nil)
       module Expression
         # Add `expression` and `loc` to all `regexp_parser` nodes
         module Base
-          attr_accessor :origin, :source
-
-          def start_index
-            # ts is a byte index; convert it to a character index
-            @start_index ||= source.byteslice(0, ts).length
-          end
+          attr_accessor :origin
 
           # Shortcut to `loc.expression`
           def expression
-            @expression ||= begin
-              origin.adjust(begin_pos: start_index, end_pos: start_index + full_length)
-            end
+            @expression ||= origin.adjust(begin_pos: ts, end_pos: ts + full_length)
           end
 
           # @returns a location map like `parser` does, with:
diff --git a/rubocop.gemspec b/rubocop.gemspec
index 67581939867..114bf03e44a 100644
--- a/rubocop.gemspec
+++ b/rubocop.gemspec
@@ -33,7 +33,7 @@ Gem::Specification.new do |s|
   s.add_runtime_dependency('parallel', '~> 1.10')
   s.add_runtime_dependency('parser', '>= 2.7.1.5')
   s.add_runtime_dependency('rainbow', '>= 2.2.2', '< 4.0')
-  s.add_runtime_dependency('regexp_parser', '>= 1.8')
+  s.add_runtime_dependency('regexp_parser', '>= 2.0')
   s.add_runtime_dependency('rexml')
   s.add_runtime_dependency('rubocop-ast', '>= 1.1.1')
   s.add_runtime_dependency('ruby-progressbar', '~> 1.7')