diff --git a/lua/nvim-treesitter/parsers.lua b/lua/nvim-treesitter/parsers.lua
index 31b691209..4a816384d 100644
--- a/lua/nvim-treesitter/parsers.lua
+++ b/lua/nvim-treesitter/parsers.lua
@@ -1621,6 +1621,22 @@ list.odin = {
   maintainers = { "@amaanq" },
 }
 
+-- Define filetype for ORCA input files
+vim.filetype.add({
+	extension = {
+		inp = "inp",
+	},
+})
+
+list.orca = {
+  install_info = {
+    url = "https://github.com/kszenes/tree-sitter-orca.git",
+    files = { "src/parser.c" }
+  },
+  filetype = "inp",
+  maintainers = { "@kszenes" }
+}
+
 list.pascal = {
   install_info = {
     url = "https://github.com/Isopod/tree-sitter-pascal",
diff --git a/queries/orca/folds.scm b/queries/orca/folds.scm
new file mode 100644
index 000000000..a9b687ef7
--- /dev/null
+++ b/queries/orca/folds.scm
@@ -0,0 +1,9 @@
+[
+  (input_block)
+  (geom_block) 
+  (subblock)
+  (compound_script)
+  (compound_step_block)
+  (compound_for_loop)
+  (compound_if_block)
+] @fold
diff --git a/queries/orca/highlights.scm b/queries/orca/highlights.scm
new file mode 100644
index 000000000..93b9b9a1c
--- /dev/null
+++ b/queries/orca/highlights.scm
@@ -0,0 +1,131 @@
+(comment) @comment
+(integer) @number
+(float) @float
+(element) @string
+(simple_line) @variable.parameter @markup.strong
+(input_title) @keyword
+(input_key) @property 
+(quoted_string) @string 
+(geom_line_types) @type
+"xyz" @type
+"int" @type
+"gzmt" @type
+"end" @keyword
+"*" @keyword
+(string) @number 
+
+;; Variables (FIRST - higher priority than general rules) - using @function for prominence
+(variable_ref (variable_name) @operator)  ; {r} in geometry blocks
+(variable_ref "{" @punctuation.bracket)
+(variable_ref "}" @punctuation.bracket)
+(variable_def (variable_name) @operator)  ; r in variable definitions
+(variable_range (float) @float)
+(variable_array (float) @float)
+
+;; Variable definitions in %paras blocks (when parsed as regular kv_pair)
+(input_block (input_title (word) @_paras) (input_body (kv_pair (input_key (word) @operator))) (#eq? @_paras "paras"))
+;; Variable definitions in pardef subblocks  
+(subblock (word) @_pardef (input_body (kv_pair (input_key (word) @operator))) (#eq? @_pardef "pardef"))
+
+";" @punctuation.delimiter
+
+;; Brace blocks
+(brace_block "{" @property)
+(brace_block "}" @property)
+(brace_value (float) @float)
+(brace_value (integer) @number)
+(constraint_content) @string
+"," @punctuation.delimiter
+
+;; General word values (LAST - lower priority)
+(value_atom (word) @number)  ; Words used as values get same color as other values
+
+;; Internal coordinate highlighting
+(int_line connect1: (integer) @operator)
+(int_line connect2: (integer) @operator)  
+(int_line connect3: (integer) @operator)
+(int_line (coord_value (float) @float))
+(int_line (coord_value (variable_ref) @operator))
+
+;; Zmatrix coordinate highlighting - alternating pattern like internal coords
+(zmat_line2 zmat_atom1: (integer) @operator)
+(zmat_line2 (coord_value (float) @float))
+(zmat_line2 (coord_value (variable_ref) @operator))
+
+(zmat_line3 zmat_atom1: (integer) @operator)
+(zmat_line3 zmat_atom2: (integer) @operator)
+(zmat_line3 (coord_value (float) @float))
+(zmat_line3 (coord_value (variable_ref) @operator))
+
+(zmat_line4 zmat_atom1: (integer) @operator)
+(zmat_line4 zmat_atom2: (integer) @operator)
+(zmat_line4 zmat_atom3: (integer) @operator)
+(zmat_line4 (coord_value (float) @float))
+(zmat_line4 (coord_value (variable_ref) @operator))
+
+;; Subblocks
+(subblock name: (word) @character)
+(subblock "end" @character)
+
+;; Compound script highlighting - use node types instead of regexes
+(compound_script) @keyword  
+(compound_variable_declaration) @keyword
+(compound_step_block) @keyword
+(compound_end) @keyword
+(compound_variable_declaration (variable_name) @function)
+(compound_variable_reference (variable_name) @function)
+(compound_variable_reference "&{" @punctuation.bracket)
+(compound_variable_reference "}" @punctuation.bracket)
+(compound_boolean) @boolean
+(compound_assignment (variable_name) @function)
+(coord_value (compound_variable_reference) @function)
+
+;; Control flow structures
+(compound_for_loop) @keyword
+(compound_if_block) @keyword
+
+;; For loop keywords and components
+(compound_for_loop (variable_name) @function)
+
+;; If/else condition components
+(compound_condition) @conditional
+(compound_comparison) @operator
+
+;; Array access
+(compound_array_access (variable_name) @function)
+(compound_array_access "[" @punctuation.bracket)
+(compound_array_access "]" @punctuation.bracket)
+
+;; Function calls
+(compound_function_call (variable_name) @function.call)
+(compound_function_call "(" @punctuation.bracket)
+(compound_function_call ")" @punctuation.bracket)
+
+;; Array assignments
+(compound_array_assignment (compound_array_access (variable_name) @function))
+
+;; Variables in expressions - general pattern to catch all variable usage
+(compound_primary_expr (variable_name) @function)
+
+;; Operators in expressions
+(compound_multiplicative_expr "*" @operator)
+(compound_multiplicative_expr "/" @operator)
+(compound_additive_expr "+" @operator)
+(compound_additive_expr "-" @operator)
+
+;; Assignment operators
+(compound_assignment "=" @operator)
+(compound_array_assignment "=" @operator)
+
+;; Parentheses in expressions and conditions
+(compound_primary_expr "(" @punctuation.bracket)
+(compound_primary_expr ")" @punctuation.bracket)
+(compound_if_block "(" @punctuation.bracket)
+(compound_if_block ")" @punctuation.bracket)
+
+;; Semicolons
+(compound_assignment ";" @punctuation.delimiter)
+(compound_array_assignment ";" @punctuation.delimiter)
+(compound_variable_declaration ";" @punctuation.delimiter)
+(compound_function_call ";" @punctuation.delimiter)
+
diff --git a/queries/orca/indents.scm b/queries/orca/indents.scm
new file mode 100644
index 000000000..255d0a368
--- /dev/null
+++ b/queries/orca/indents.scm
@@ -0,0 +1,21 @@
+[
+  (input_block)
+  (subblock) 
+  (geom_block)
+  (compound_script)
+  (compound_step_block)
+  (compound_for_loop)
+  (compound_if_block)
+] @indent.begin
+
+[
+  (input_block)
+  (subblock) 
+  (geom_block)
+  (compound_script)
+  (compound_step_block)
+  (compound_for_loop)
+  (compound_if_block)
+] @indent.end
+
+"*" @indent.end
\ No newline at end of file