1877–78 FA Cup#Third round

{{No footnotes|date=October 2023}}

{{Infobox football tournament season

| title = 1877–78 FA Cup

| year =

| other_title =

| image =

| imagesize =

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| country = England
Wales

| num_teams = 43

| defending_champions = Wanderers

| winners = Wanderers

| count = 5

| second = Royal Engineers

| matches =

| goals =

| scoring_leader =

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| prev_season = 1876–77

| next_season = 1878–79

}}

The 1877–78 Football Association Challenge Cup was the seventh staging of the FA Cup, England's oldest football tournament. Forty-three teams entered, six more than the previous season, although four of the forty-three never played a match.