diff --git a/CHANGELOG.md b/CHANGELOG.md
index 153dc96a3c3..bb895c0141c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -29,6 +29,8 @@ release.
   ([#2874](https://github.com/open-telemetry/opentelemetry-specification/pull/2874))
 - Add `process.paging.faults` metric to semantic conventions
   ([#2827](https://github.com/open-telemetry/opentelemetry-specification/pull/2827))
+- Add `process.uptime` and `system.uptime` metrics to semantic conventions
+  ([#2824](https://github.com/open-telemetry/opentelemetry-specification/pull/2824))
 
 ### Compatibility
 
diff --git a/specification/metrics/semantic_conventions/process-metrics.md b/specification/metrics/semantic_conventions/process-metrics.md
index 0f44943eb01..8345e36f33e 100644
--- a/specification/metrics/semantic_conventions/process-metrics.md
+++ b/specification/metrics/semantic_conventions/process-metrics.md
@@ -43,6 +43,7 @@ Below is a table of Process metric instruments.
 | `process.open_file_descriptors` | UpDownCounter                                      | {count}   | Number of file descriptors in use by the process.                                                                                   |                                                                                                                                                                                                 |
 | `process.context_switches`      | Counter                                            | {count}   | Number of times the process has been context switched.                                                                              | `type` SHOULD be one of: `involuntary`, `voluntary`                                                                                                                                             |
 | `process.paging.faults`         | Counter                                            | {faults}  | Number of page faults the process has made.                                                                                         | `type`, if specified, SHOULD be one of: `major` (for major, or hard, page faults), `minor` (for minor, or soft, page faults).                                                                   |
+| `process.uptime`                | Counter                                            | s         | Number of seconds that the process has been running.                                                                                |                                                                                                                                                                                                 |
 
 ## Attributes
 
diff --git a/specification/metrics/semantic_conventions/system-metrics.md b/specification/metrics/semantic_conventions/system-metrics.md
index 739cef68596..f5e2705692e 100644
--- a/specification/metrics/semantic_conventions/system-metrics.md
+++ b/specification/metrics/semantic_conventions/system-metrics.md
@@ -16,6 +16,7 @@ instruments not explicitly defined in the specification.
 <!-- toc -->
 
 - [Metric Instruments](#metric-instruments)
+  * [`system.` - General system metrics](#system---general-system-metrics)
   * [`system.cpu.` - Processor metrics](#systemcpu---processor-metrics)
   * [`system.memory.` - Memory metrics](#systemmemory---memory-metrics)
   * [`system.paging.` - Paging/swap metrics](#systempaging---pagingswap-metrics)
@@ -29,6 +30,14 @@ instruments not explicitly defined in the specification.
 
 ## Metric Instruments
 
+### `system.` - General system metrics
+
+**Description:** General system metrics.
+
+| Name                   | Description                                                                                              | Units | Instrument Type ([*](README.md#instrument-types)) | Value Type | Attribute Key(s) | Attribute Values                    |
+| ---------------------- | -------------------------------------------------------------------------------------------------------- | ----- | ------------------------------------------------- | ---------- | ---------------- | ----------------------------------- |
+| system.uptime          | Number of seconds that the system has been running.                                                      | s     | Counter                                           | Int64      |                  |                                     |
+
 ### `system.cpu.` - Processor metrics
 
 **Description:** System level processor metrics.