diff --git a/src/th/onemanga/build.gradle b/src/th/onemanga/build.gradle
new file mode 100644
index 000000000..077b626a6
--- /dev/null
+++ b/src/th/onemanga/build.gradle
@@ -0,0 +1,10 @@
+ext {
+    extName = 'OneManga'
+    extClass = '.OneManga'
+    themePkg = 'mangathemesia'
+    baseUrl = 'https://one-manga.com'
+    overrideVersionCode = 0
+    isNsfw = true
+}
+
+apply from: "$rootDir/common.gradle"
diff --git a/src/th/onemanga/res/mipmap-hdpi/ic_launcher.png b/src/th/onemanga/res/mipmap-hdpi/ic_launcher.png
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diff --git a/src/th/onemanga/res/mipmap-xhdpi/ic_launcher.png b/src/th/onemanga/res/mipmap-xhdpi/ic_launcher.png
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diff --git a/src/th/onemanga/res/mipmap-xxhdpi/ic_launcher.png b/src/th/onemanga/res/mipmap-xxhdpi/ic_launcher.png
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diff --git a/src/th/onemanga/res/mipmap-xxxhdpi/ic_launcher.png b/src/th/onemanga/res/mipmap-xxxhdpi/ic_launcher.png
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diff --git a/src/th/onemanga/src/eu/kanade/tachiyomi/extension/th/onemanga/OneManga.kt b/src/th/onemanga/src/eu/kanade/tachiyomi/extension/th/onemanga/OneManga.kt
new file mode 100644
index 000000000..75a51a3fc
--- /dev/null
+++ b/src/th/onemanga/src/eu/kanade/tachiyomi/extension/th/onemanga/OneManga.kt
@@ -0,0 +1,75 @@
+package eu.kanade.tachiyomi.extension.th.onemanga
+
+import eu.kanade.tachiyomi.multisrc.mangathemesia.MangaThemesia
+import eu.kanade.tachiyomi.network.GET
+import eu.kanade.tachiyomi.source.model.Filter
+import eu.kanade.tachiyomi.source.model.FilterList
+import eu.kanade.tachiyomi.source.model.SManga
+import okhttp3.HttpUrl.Companion.toHttpUrl
+import okhttp3.Request
+import org.jsoup.nodes.Document
+import java.text.SimpleDateFormat
+import java.util.Locale
+import java.util.TimeZone
+
+class OneManga : MangaThemesia(
+    "One-Manga",
+    "https://one-manga.com",
+    "th",
+    dateFormat = SimpleDateFormat("MMMM d, yyyy", Locale("th")).apply {
+        timeZone = TimeZone.getTimeZone("Asia/Bangkok")
+    },
+) {
+    override fun mangaDetailsParse(document: Document): SManga {
+        return super.mangaDetailsParse(document).apply {
+            // Add 'color' badge as a genre
+            if (document.selectFirst(".thumb .colored") != null) {
+                genre = genre?.plus(", Color")
+            }
+        }
+    }
+
+    override fun searchMangaRequest(page: Int, query: String, filters: FilterList): Request {
+        val url = baseUrl.toHttpUrl().newBuilder()
+            .addPathSegment(mangaUrlDirectory.substring(1))
+            .addQueryParameter("s", query)
+            .addQueryParameter("page", page.toString())
+
+        filters.forEach { filter ->
+            when (filter) {
+                is AuthorFilter -> {
+                    url.addQueryParameter("author", filter.state)
+                }
+                is YearFilter -> {
+                    url.addQueryParameter("yearx", filter.state)
+                }
+                is StatusFilter -> {
+                    url.addQueryParameter("status", filter.selectedValue())
+                }
+                is TypeFilter -> {
+                    url.addQueryParameter("type", filter.selectedValue())
+                }
+                is OrderByFilter -> {
+                    url.addQueryParameter("order", filter.selectedValue())
+                }
+                is GenreListFilter -> {
+                    filter.state
+                        .filter { it.state != Filter.TriState.STATE_IGNORE }
+                        .forEach {
+                            val value = if (it.state == Filter.TriState.STATE_EXCLUDE) "-${it.value}" else it.value
+                            url.addQueryParameter("genre[]", value)
+                        }
+                }
+                // if site has project page, default value "hasProjectPage" = false
+                is ProjectFilter -> {
+                    if (filter.selectedValue() == "project-filter-on") {
+                        url.setPathSegment(0, projectPageString.substring(1))
+                    }
+                }
+                else -> { /* Do Nothing */ }
+            }
+        }
+        url.addPathSegment("")
+        return GET(url.build(), headers)
+    }
+}