diff --git a/spring-test/src/main/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilder.java b/spring-test/src/main/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilder.java
index d88acf31f2d..6c681e54799 100644
--- a/spring-test/src/main/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilder.java
+++ b/spring-test/src/main/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilder.java
@@ -28,7 +28,6 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
-import java.util.stream.Collectors;
 
 import javax.servlet.ServletContext;
 import javax.servlet.ServletRequest;
@@ -101,9 +100,6 @@ public class MockHttpServletRequestBuilder
 	@Nullable
 	private Boolean secure;
 
-	@Nullable
-	private String queryString = "";
-
 	@Nullable
 	private Principal principal;
 
@@ -123,6 +119,8 @@ public class MockHttpServletRequestBuilder
 
 	private final MultiValueMap<String, String> parameters = new LinkedMultiValueMap<>();
 
+	private final MultiValueMap<String, String> queryParams = new LinkedMultiValueMap<>();
+
 	private final List<Cookie> cookies = new ArrayList<>();
 
 	private final List<Locale> locales = new ArrayList<>();
@@ -252,6 +250,10 @@ public class MockHttpServletRequestBuilder
 
 	/**
 	 * Set the request body.
+	 * <p>If content is provided and {@link #contentType(MediaType)} is set to
+	 * {@code application/x-www-form-urlencoded}, the content will be parsed
+	 * and used to populate the {@link #param(String, String...) request
+	 * parameters} map.
 	 * @param content the body content
 	 */
 	public MockHttpServletRequestBuilder content(byte[] content) {
@@ -261,6 +263,10 @@ public class MockHttpServletRequestBuilder
 
 	/**
 	 * Set the request body as a UTF-8 String.
+	 * <p>If content is provided and {@link #contentType(MediaType)} is set to
+	 * {@code application/x-www-form-urlencoded}, the content will be parsed
+	 * and used to populate the {@link #param(String, String...) request
+	 * parameters} map.
 	 * @param content the body content
 	 */
 	public MockHttpServletRequestBuilder content(String content) {
@@ -270,6 +276,10 @@ public class MockHttpServletRequestBuilder
 
 	/**
 	 * Set the 'Content-Type' header of the request.
+	 * <p>If content is provided and {@code contentType} is set to
+	 * {@code application/x-www-form-urlencoded}, the content will be parsed
+	 * and used to populate the {@link #param(String, String...) request
+	 * parameters} map.
 	 * @param contentType the content type
 	 */
 	public MockHttpServletRequestBuilder contentType(MediaType contentType) {
@@ -332,8 +342,18 @@ public class MockHttpServletRequestBuilder
 	}
 
 	/**
-	 * Add a request parameter to the {@link MockHttpServletRequest}.
-	 * <p>If called more than once, new values get added to existing ones.
+	 * Add a request parameter to {@link MockHttpServletRequest#getParameterMap()}.
+	 * <p>In the Servlet API, a request parameter may be parsed from the query
+	 * string and/or from the body of an {@code application/x-www-form-urlencoded}
+	 * request. This method simply adds to the request parameter map. You may
+	 * also use add Servlet request parameters by specifying the query or form
+	 * data through one of the following:
+	 * <ul>
+	 * <li>Supply a URL with a query to {@link MockMvcRequestBuilders}.
+	 * <li>Add query params via {@link #queryParam} or {@link #queryParams}.
+	 * <li>Provide {@link #content} with {@link #contentType}
+	 * {@code application/x-www-form-urlencoded}.
+	 * </ul>
 	 * @param name the parameter name
 	 * @param values one or more values
 	 */
@@ -343,9 +363,7 @@ public class MockHttpServletRequestBuilder
 	}
 
 	/**
-	 * Add a map of request parameters to the {@link MockHttpServletRequest},
-	 * for example when testing a form submission.
-	 * <p>If called more than once, new values get added to existing ones.
+	 * Variant of {@link #param(String, String...)} with a {@link MultiValueMap}.
 	 * @param params the parameters to add
 	 * @since 4.2.4
 	 */
@@ -359,36 +377,29 @@ public class MockHttpServletRequestBuilder
 	}
 
 	/**
-	 * Add a query parameter to the {@link MockHttpServletRequest}.
-	 * <p>If called more than once, new values get added to existing ones.
+	 * Append to the query string and also add to the
+	 * {@link #param(String, String...) request parameters} map. The parameter
+	 * name and value are encoded when they are added to the query string.
 	 * @param name the parameter name
 	 * @param values one or more values
+	 * @since 5.2.2
 	 */
 	public MockHttpServletRequestBuilder queryParam(String name, String... values) {
 		param(name, values);
-		String builder = Arrays.stream(values).map(value -> UriUtils.encode(name, StandardCharsets.UTF_8) +
-						((value != null) ? ("=" + UriUtils.encode(value, StandardCharsets.UTF_8)) : "") + "&"
-				).collect(Collectors.joining());
-		queryString += builder;
+		this.queryParams.addAll(name, Arrays.asList(values));
 		return this;
 	}
 
 	/**
-	 * Add a map of query parameters to the {@link MockHttpServletRequest},
-	 * for example when testing a form submission.
-	 * <p>If called more than once, new values get added to existing ones.
+	 * Append to the query string and also add to the
+	 * {@link #params(MultiValueMap)}  request parameters} map. The parameter
+	 * name and value are encoded when they are added to the query string.
 	 * @param params the parameters to add
-	 * @since 4.2.4
+	 * @since 5.2.2
 	 */
 	public MockHttpServletRequestBuilder queryParams(MultiValueMap<String, String> params) {
 		params(params);
-		StringBuilder builder = new StringBuilder();
-		params.forEach((key, values) -> values.forEach(value -> {
-			builder.append(UriUtils.encode(key, StandardCharsets.UTF_8))
-					.append(((value != null) ? ("=" + UriUtils.encode(value, StandardCharsets.UTF_8)) : ""))
-					.append("&");
-		}));
-		queryString += builder.toString();
+		this.queryParams.addAll(params);
 		return this;
 	}
 
@@ -581,6 +592,12 @@ public class MockHttpServletRequestBuilder
 				this.parameters.put(paramName, entry.getValue());
 			}
 		}
+		for (Map.Entry<String, List<String>> entry : parentBuilder.queryParams.entrySet()) {
+			String paramName = entry.getKey();
+			if (!this.queryParams.containsKey(paramName)) {
+				this.queryParams.put(paramName, entry.getValue());
+			}
+		}
 		for (Cookie cookie : parentBuilder.cookies) {
 			if (!containsCookie(cookie)) {
 				this.cookies.add(cookie);
@@ -670,28 +687,22 @@ public class MockHttpServletRequestBuilder
 			}
 		});
 
-		if (this.url.getRawQuery() != null) {
-			request.setQueryString(this.url.getRawQuery());
+		String query = this.url.getRawQuery();
+		if (!this.queryParams.isEmpty()) {
+			String s = UriComponentsBuilder.newInstance().queryParams(this.queryParams).build().encode().getQuery();
+			query = StringUtils.isEmpty(query) ? s : query + "&" + s;
+		}
+		if (query != null) {
+			request.setQueryString(query);
 		}
 		addRequestParams(request, UriComponentsBuilder.fromUri(this.url).build().getQueryParams());
+
 		this.parameters.forEach((name, values) -> {
 			for (String value : values) {
 				request.addParameter(name, value);
 			}
 		});
 
-		StringBuilder queryBuilder = new StringBuilder();
-		if (request.getQueryString() != null) {
-			queryBuilder.append(request.getQueryString());
-		}
-		if (this.queryString != null && !"".equals(this.queryString)) {
-			if (queryBuilder.length() > 0) {
-				queryBuilder.append("&");
-			}
-			queryBuilder.append(this.queryString, 0, this.queryString.length() - 1);
-			request.setQueryString(queryBuilder.toString());
-		}
-
 		if (this.content != null && this.content.length > 0) {
 			String requestContentType = request.getContentType();
 			if (requestContentType != null) {
diff --git a/spring-test/src/test/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilderTests.java b/spring-test/src/test/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilderTests.java
index 34c29ce4b3c..405bfdb46d7 100644
--- a/spring-test/src/test/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilderTests.java
+++ b/spring-test/src/test/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilderTests.java
@@ -236,7 +236,7 @@ public class MockHttpServletRequestBuilderTests {
 	}
 
 	@Test
-	public void requestParameterToQuery() {
+	public void queryParameter() {
 		this.builder = new MockHttpServletRequestBuilder(HttpMethod.GET, "/");
 		this.builder.queryParam("foo", "bar");
 		this.builder.queryParam("foo", "baz");
@@ -248,7 +248,7 @@ public class MockHttpServletRequestBuilderTests {
 	}
 
 	@Test
-	public void requestParameterMapToQuery() {
+	public void queryParameterMap() {
 		this.builder = new MockHttpServletRequestBuilder(HttpMethod.GET, "/");
 		MultiValueMap<String, String> queryParams = new LinkedMultiValueMap<>();
 		List<String> values = new ArrayList<>();
@@ -264,7 +264,7 @@ public class MockHttpServletRequestBuilderTests {
 	}
 
 	@Test
-	public void requestParameterToQueryList() {
+	public void queryParameterList() {
 		this.builder = new MockHttpServletRequestBuilder(HttpMethod.GET, "/");
 		this.builder.queryParam("foo[0]", "bar");
 		this.builder.queryParam("foo[1]", "baz");