diff --git a/clientv3/snapshot/member_test.go b/clientv3/snapshot/member_test.go
index a42066a56..04c9a2da1 100644
--- a/clientv3/snapshot/member_test.go
+++ b/clientv3/snapshot/member_test.go
@@ -65,7 +65,6 @@ func TestSnapshotV3RestoreMultiMemberAdd(t *testing.T) {
 	cfg := embed.NewConfig()
 	cfg.Logger = "zap"
 	cfg.LogOutputs = []string{"/dev/null"}
-	cfg.Debug = false
 	cfg.Name = "3"
 	cfg.InitialClusterToken = testClusterTkn
 	cfg.ClusterState = "existing"
diff --git a/clientv3/snapshot/v3_snapshot_test.go b/clientv3/snapshot/v3_snapshot_test.go
index 0a4c3096c..36eeac5bd 100644
--- a/clientv3/snapshot/v3_snapshot_test.go
+++ b/clientv3/snapshot/v3_snapshot_test.go
@@ -47,7 +47,6 @@ func TestSnapshotV3RestoreSingle(t *testing.T) {
 	cfg := embed.NewConfig()
 	cfg.Logger = "zap"
 	cfg.LogOutputs = []string{"/dev/null"}
-	cfg.Debug = false
 	cfg.Name = "s1"
 	cfg.InitialClusterToken = testClusterTkn
 	cfg.ClusterState = "existing"
@@ -200,7 +199,6 @@ func createSnapshotFile(t *testing.T, kvs []kv) string {
 	cfg := embed.NewConfig()
 	cfg.Logger = "zap"
 	cfg.LogOutputs = []string{"/dev/null"}
-	cfg.Debug = false
 	cfg.Name = "default"
 	cfg.ClusterState = "new"
 	cfg.LCUrls, cfg.ACUrls = cURLs, cURLs
@@ -267,7 +265,6 @@ func restoreCluster(t *testing.T, clusterN int, dbPath string) (
 		cfg := embed.NewConfig()
 		cfg.Logger = "zap"
 		cfg.LogOutputs = []string{"/dev/null"}
-		cfg.Debug = false
 		cfg.Name = fmt.Sprintf("%d", i)
 		cfg.InitialClusterToken = testClusterTkn
 		cfg.ClusterState = "existing"
diff --git a/embed/config.go b/embed/config.go
index 2b44cf05d..dba3a867a 100644
--- a/embed/config.go
+++ b/embed/config.go
@@ -290,8 +290,8 @@ type Config struct {
 	ListenMetricsUrls     []url.URL
 	ListenMetricsUrlsJSON string `json:"listen-metrics-urls"`
 
-	// Logger is logger options: "zap", "capnslog".
-	// WARN: "capnslog" is being deprecated in v3.5.
+	// Logger is logger options: currently only supports "zap".
+	// "capnslog" is removed in v3.5.
 	Logger string `json:"logger"`
 	// LogLevel configures log level. Only supports debug, info, warn, error, panic, or fatal. Default 'info'.
 	LogLevel string `json:"log-level"`
@@ -322,19 +322,6 @@ type Config struct {
 
 	// EnableGRPCGateway is false to disable grpc gateway.
 	EnableGRPCGateway bool `json:"enable-grpc-gateway"`
-
-	// TO BE DEPRECATED
-
-	// DeprecatedLogOutput is to be deprecated in v3.5.
-	// Just here for safe migration in v3.4.
-	DeprecatedLogOutput []string `json:"log-output"`
-	// Debug is true, to enable debug level logging.
-	// WARNING: to be deprecated in 3.5. Use "--log-level=debug" instead.
-	Debug bool `json:"debug"`
-	// LogPkgLevels is being deprecated in v3.5.
-	// Only valid if "logger" option is "capnslog".
-	// WARN: DO NOT USE THIS!
-	LogPkgLevels string `json:"log-package-levels"`
 }
 
 // configYAML holds the config suitable for yaml parsing
@@ -411,14 +398,11 @@ func NewConfig() *Config {
 
 		PreVote: false, // TODO: enable by default in v3.5
 
-		loggerMu:            new(sync.RWMutex),
-		logger:              nil,
-		Logger:              "capnslog",
-		DeprecatedLogOutput: []string{DefaultLogOutput},
-		LogOutputs:          []string{DefaultLogOutput},
-		Debug:               false,
-		LogLevel:            logutil.DefaultLogLevel,
-		LogPkgLevels:        "",
+		loggerMu:   new(sync.RWMutex),
+		logger:     nil,
+		Logger:     "zap",
+		LogOutputs: []string{DefaultLogOutput},
+		LogLevel:   logutil.DefaultLogLevel,
 	}
 	cfg.InitialCluster = cfg.InitialClusterFromName(cfg.Name)
 	return cfg
diff --git a/embed/config_logging.go b/embed/config_logging.go
index e42103cb1..cdde4112d 100644
--- a/embed/config_logging.go
+++ b/embed/config_logging.go
@@ -16,16 +16,11 @@ package embed
 
 import (
 	"crypto/tls"
-	"errors"
 	"fmt"
-	"io/ioutil"
-	"os"
-	"reflect"
 	"sync"
 
 	"go.etcd.io/etcd/pkg/logutil"
 
-	"github.com/coreos/pkg/capnslog"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
 	"google.golang.org/grpc"
@@ -46,91 +41,9 @@ var grpcLogOnce = new(sync.Once)
 // setupLogging initializes etcd logging.
 // Must be called after flag parsing or finishing configuring embed.Config.
 func (cfg *Config) setupLogging() error {
-	// handle "DeprecatedLogOutput" in v3.4
-	// TODO: remove "DeprecatedLogOutput" in v3.5
-	len1 := len(cfg.DeprecatedLogOutput)
-	len2 := len(cfg.LogOutputs)
-	if len1 != len2 {
-		switch {
-		case len1 > len2: // deprecate "log-output" flag is used
-			fmt.Fprintln(os.Stderr, "'--log-output' flag has been deprecated! Please use '--log-outputs'!")
-			cfg.LogOutputs = cfg.DeprecatedLogOutput
-		case len1 < len2: // "--log-outputs" flag has been set with multiple writers
-			cfg.DeprecatedLogOutput = []string{}
-		}
-	} else {
-		if len1 > 1 {
-			return errors.New("both '--log-output' and '--log-outputs' are set; only set '--log-outputs'")
-		}
-		if len1 < 1 {
-			return errors.New("either '--log-output' or '--log-outputs' flag must be set")
-		}
-		if reflect.DeepEqual(cfg.DeprecatedLogOutput, cfg.LogOutputs) && cfg.DeprecatedLogOutput[0] != DefaultLogOutput {
-			return fmt.Errorf("'--log-output=%q' and '--log-outputs=%q' are incompatible; only set --log-outputs", cfg.DeprecatedLogOutput, cfg.LogOutputs)
-		}
-		if !reflect.DeepEqual(cfg.DeprecatedLogOutput, []string{DefaultLogOutput}) {
-			fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--log-output' flag is set to %q\n", cfg.DeprecatedLogOutput)
-			fmt.Fprintln(os.Stderr, "Please use '--log-outputs' flag")
-		}
-	}
-
-	// TODO: remove after deprecating log related flags in v3.5
-	if cfg.Debug {
-		fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--debug' flag is set to %v (use '--log-level=debug' instead\n", cfg.Debug)
-	}
-	if cfg.Debug && cfg.LogLevel != "debug" {
-		fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--debug' flag is set to %v with inconsistent '--log-level=%s' flag\n", cfg.Debug, cfg.LogLevel)
-	}
-	if cfg.Logger == "capnslog" {
-		fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--logger=%s' flag is set; use '--logger=zap' flag instead\n", cfg.Logger)
-	}
-	if cfg.LogPkgLevels != "" {
-		fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--log-package-levels=%s' flag is set; use '--logger=zap' flag instead\n", cfg.LogPkgLevels)
-	}
-
 	switch cfg.Logger {
-	case "capnslog": // TODO: deprecate this in v3.5
-		cfg.ClientTLSInfo.HandshakeFailure = logTLSHandshakeFailure
-		cfg.PeerTLSInfo.HandshakeFailure = logTLSHandshakeFailure
-
-		if cfg.Debug {
-			capnslog.SetGlobalLogLevel(capnslog.DEBUG)
-			grpc.EnableTracing = true
-			// enable info, warning, error
-			grpclog.SetLoggerV2(grpclog.NewLoggerV2(os.Stderr, os.Stderr, os.Stderr))
-		} else {
-			capnslog.SetGlobalLogLevel(logutil.ConvertToCapnslogLogLevel(cfg.LogLevel))
-			// only discard info
-			grpclog.SetLoggerV2(grpclog.NewLoggerV2(ioutil.Discard, os.Stderr, os.Stderr))
-		}
-
-		// TODO: deprecate with "capnslog"
-		if cfg.LogPkgLevels != "" {
-			repoLog := capnslog.MustRepoLogger("go.etcd.io/etcd")
-			settings, err := repoLog.ParseLogLevelConfig(cfg.LogPkgLevels)
-			if err != nil {
-				plog.Warningf("couldn't parse log level string: %s, continuing with default levels", err.Error())
-				return nil
-			}
-			repoLog.SetLogLevel(settings)
-		}
-
-		if len(cfg.LogOutputs) != 1 {
-			return fmt.Errorf("--logger=capnslog supports only 1 value in '--log-outputs', got %q", cfg.LogOutputs)
-		}
-		// capnslog initially SetFormatter(NewDefaultFormatter(os.Stderr))
-		// where NewDefaultFormatter returns NewJournaldFormatter when syscall.Getppid() == 1
-		// specify 'stdout' or 'stderr' to skip journald logging even when running under systemd
-		output := cfg.LogOutputs[0]
-		switch output {
-		case StdErrLogOutput:
-			capnslog.SetFormatter(capnslog.NewPrettyFormatter(os.Stderr, cfg.Debug))
-		case StdOutLogOutput:
-			capnslog.SetFormatter(capnslog.NewPrettyFormatter(os.Stdout, cfg.Debug))
-		case DefaultLogOutput:
-		default:
-			return fmt.Errorf("unknown log-output %q (only supports %q, %q, %q)", output, DefaultLogOutput, StdErrLogOutput, StdOutLogOutput)
-		}
+	case "capnslog": // removed in v3.5
+		return fmt.Errorf("--logger=capnslog is removed in v3.5")
 
 	case "zap":
 		if len(cfg.LogOutputs) == 0 {
@@ -175,10 +88,7 @@ func (cfg *Config) setupLogging() error {
 			copied.ErrorOutputPaths = errOutputPaths
 			copied = logutil.MergeOutputPaths(copied)
 			copied.Level = zap.NewAtomicLevelAt(logutil.ConvertToZapLevel(cfg.LogLevel))
-			if cfg.Debug || cfg.LogLevel == "debug" {
-				// enable tracing even when "--debug --log-level info"
-				// in order to keep backward compatibility with <= v3.3
-				// TODO: remove "Debug" check in v3.5
+			if cfg.LogLevel == "debug" {
 				grpc.EnableTracing = true
 			}
 			if cfg.ZapLoggerBuilder == nil {
@@ -221,10 +131,7 @@ func (cfg *Config) setupLogging() error {
 			}
 
 			lvl := zap.NewAtomicLevelAt(logutil.ConvertToZapLevel(cfg.LogLevel))
-			if cfg.Debug || cfg.LogLevel == "debug" {
-				// enable tracing even when "--debug --log-level info"
-				// in order to keep backward compatibility with <= v3.3
-				// TODO: remove "Debug" check in v3.5
+			if cfg.LogLevel == "debug" {
 				grpc.EnableTracing = true
 			}
 
diff --git a/embed/config_test.go b/embed/config_test.go
index eacf181ba..263f9b275 100644
--- a/embed/config_test.go
+++ b/embed/config_test.go
@@ -159,7 +159,6 @@ func TestAutoCompactionModeInvalid(t *testing.T) {
 	cfg := NewConfig()
 	cfg.Logger = "zap"
 	cfg.LogOutputs = []string{"/dev/null"}
-	cfg.Debug = false
 	cfg.AutoCompactionMode = "period"
 	err := cfg.Validate()
 	if err == nil {
diff --git a/embed/etcd.go b/embed/etcd.go
index c9301bc25..6c43742bb 100644
--- a/embed/etcd.go
+++ b/embed/etcd.go
@@ -201,7 +201,6 @@ func StartEtcd(inCfg *Config) (e *Etcd, err error) {
 		LoggerConfig:               cfg.loggerConfig,
 		LoggerCore:                 cfg.loggerCore,
 		LoggerWriteSyncer:          cfg.loggerWriteSyncer,
-		Debug:                      cfg.Debug,
 		ForceNewCluster:            cfg.ForceNewCluster,
 		EnableGRPCGateway:          cfg.EnableGRPCGateway,
 		EnableLeaseCheckpoint:      cfg.ExperimentalEnableLeaseCheckpoint,
@@ -691,10 +690,10 @@ func configureClientListeners(cfg *Config) (sctxs map[string]*serveCtx, err erro
 			sctx.userHandlers[k] = cfg.UserHandlers[k]
 		}
 		sctx.serviceRegister = cfg.ServiceRegister
-		if cfg.EnablePprof || cfg.Debug {
+		if cfg.EnablePprof || cfg.LogLevel == "debug" {
 			sctx.registerPprof()
 		}
-		if cfg.Debug {
+		if cfg.LogLevel == "debug" {
 			sctx.registerTrace()
 		}
 		sctxs[addr] = sctx
diff --git a/etcdmain/config.go b/etcdmain/config.go
index 28a10bb07..c3686abde 100644
--- a/etcdmain/config.go
+++ b/etcdmain/config.go
@@ -221,12 +221,9 @@ func newConfig() *config {
 	fs.Var(flags.NewUniqueStringsValue("*"), "host-whitelist", "Comma-separated acceptable hostnames from HTTP client requests, if server is not secure (empty means allow all).")
 
 	// logging
-	fs.StringVar(&cfg.ec.Logger, "logger", "capnslog", "Specify 'zap' for structured logging or 'capnslog'. WARN: 'capnslog' is being deprecated in v3.5.")
-	fs.Var(flags.NewUniqueStringsValue(embed.DefaultLogOutput), "log-output", "[TO BE DEPRECATED IN v3.5] use '--log-outputs'.")
+	fs.StringVar(&cfg.ec.Logger, "logger", "zap", "Currently only supports 'zap' for structured logging.")
 	fs.Var(flags.NewUniqueStringsValue(embed.DefaultLogOutput), "log-outputs", "Specify 'stdout' or 'stderr' to skip journald logging even when running under systemd, or list of comma separated output targets.")
-	fs.BoolVar(&cfg.ec.Debug, "debug", false, "[TO BE DEPRECATED IN v3.5] Enable debug-level logging for etcd. Use '--log-level=debug' instead.")
 	fs.StringVar(&cfg.ec.LogLevel, "log-level", logutil.DefaultLogLevel, "Configures log level. Only supports debug, info, warn, error, panic, or fatal. Default 'info'.")
-	fs.StringVar(&cfg.ec.LogPkgLevels, "log-package-levels", "", "[TO BE DEPRECATED IN v3.5] Specify a particular log level for each etcd package (eg: 'etcdmain=CRITICAL,etcdserver=DEBUG').")
 
 	// version
 	fs.BoolVar(&cfg.printVersion, "version", false, "Print the version and exit.")
@@ -336,8 +333,6 @@ func (cfg *config) configFromCmdLine() error {
 
 	cfg.ec.CipherSuites = flags.StringsFromFlag(cfg.cf.flagSet, "cipher-suites")
 
-	// TODO: remove this in v3.5
-	cfg.ec.DeprecatedLogOutput = flags.UniqueStringsFromFlag(cfg.cf.flagSet, "log-output")
 	cfg.ec.LogOutputs = flags.UniqueStringsFromFlag(cfg.cf.flagSet, "log-outputs")
 
 	cfg.ec.ClusterState = cfg.cf.clusterState.String()
diff --git a/etcdmain/help.go b/etcdmain/help.go
index 244b798cf..73874cb36 100644
--- a/etcdmain/help.go
+++ b/etcdmain/help.go
@@ -174,8 +174,8 @@ Profiling and Monitoring:
     List of URLs to listen on for the metrics and health endpoints.
 
 Logging:
-  --logger 'capnslog'
-    Specify 'zap' for structured logging or 'capnslog'. [WARN] 'capnslog' will be deprecated in v3.5.
+  --logger 'zap'
+    Currently only supports 'zap' for structured logging.
   --log-outputs 'default'
     Specify 'stdout' or 'stderr' to skip journald logging even when running under systemd, or list of comma separated output targets.
   --log-level 'info'
@@ -214,12 +214,7 @@ Unsafe feature:
     Force to create a new one-member cluster.
 
 CAUTIOUS with unsafe flag! It may break the guarantees given by the consensus protocol!
-
-TO BE DEPRECATED:
-
-  --debug 'false'
-    Enable debug-level logging for etcd. [WARN] Will be deprecated in v3.5. Use '--log-level=debug' instead.
-  --log-package-levels ''
-    Specify a particular log level for each etcd package (eg: 'etcdmain=CRITICAL,etcdserver=DEBUG').
 `
 )
+
+// Add back "TO BE DEPRECATED" section if needed
diff --git a/etcdserver/config.go b/etcdserver/config.go
index 88cd721c3..426059b45 100644
--- a/etcdserver/config.go
+++ b/etcdserver/config.go
@@ -147,8 +147,6 @@ type ServerConfig struct {
 	LoggerCore        zapcore.Core
 	LoggerWriteSyncer zapcore.WriteSyncer
 
-	Debug bool
-
 	ForceNewCluster bool
 
 	// EnableLeaseCheckpoint enables primary lessor to persist lease remainingTTL to prevent indefinite auto-renewal of long lived leases.
diff --git a/integration/embed_test.go b/integration/embed_test.go
index c95d78d35..2bc5f44d7 100644
--- a/integration/embed_test.go
+++ b/integration/embed_test.go
@@ -58,7 +58,6 @@ func TestEmbedEtcd(t *testing.T) {
 		tests[i].cfg = *embed.NewConfig()
 		tests[i].cfg.Logger = "zap"
 		tests[i].cfg.LogOutputs = []string{"/dev/null"}
-		tests[i].cfg.Debug = false
 	}
 
 	tests[0].cfg.Durl = "abc"
@@ -184,7 +183,6 @@ func newEmbedURLs(secure bool, n int) (urls []url.URL) {
 func setupEmbedCfg(cfg *embed.Config, curls []url.URL, purls []url.URL) {
 	cfg.Logger = "zap"
 	cfg.LogOutputs = []string{"/dev/null"}
-	cfg.Debug = false
 
 	cfg.ClusterState = "new"
 	cfg.LCUrls, cfg.ACUrls = curls, curls
diff --git a/tools/etcd-dump-metrics/etcd.go b/tools/etcd-dump-metrics/etcd.go
index 2939b60c2..638e34236 100644
--- a/tools/etcd-dump-metrics/etcd.go
+++ b/tools/etcd-dump-metrics/etcd.go
@@ -42,7 +42,6 @@ func setupEmbedCfg(cfg *embed.Config, curls, purls, ics []url.URL) {
 	cfg.Logger = "zap"
 	cfg.LogOutputs = []string{"/dev/null"}
 	// []string{"stderr"} to enable server logging
-	cfg.Debug = false
 
 	var err error
 	cfg.Dir, err = ioutil.TempDir(os.TempDir(), fmt.Sprintf("%016X", time.Now().UnixNano()))