STORY: Navalny could be seen smoothing down his hair as he joined proceedings by video link from prison in Pokrov, around 100 km (60 miles) east of Moscow.
Navalny's lawyers were also present in the courtroom.
Reporters were only allowed to film in the courtroom before proceedings started, and it was later announced that a decision on the appeal would only be announced on May 24.
Navalny was sentenced to an additional nine years in prison on fraud charges in March, in a ruling that looked set to keep President Vladimir Putin's most prominent opponent out of active politics for years ahead.
The Kremlin critic, who was also found guilty of contempt of court, had already been serving a three-and-a-half-year sentence for parole violations related to charges he says were trumped up to thwart his political ambitions.