| Honorific-Prefix: | The Most Reverend |
| Antanas Vaičius | |
| Diocesan Bishop of Telšiai | |
| Appointed: | 5 July 1982 (as Apostolic Administrator) 10 March 1989 (as Diocesan Bishop) |
| Ended: | 26 May 2001 |
| Predecessor: | Juozapas Pletkus (as Ap.Administrator) |
| Successor: | Jonas Boruta, SJ |
| Ordination: | 24 September 1950 |
| Ordained By: | Kazimieras Paltarokas |
| Consecration: | 25 July 1982 |
| Birth Name: | Antanas Vaičius |
| Birth Date: | 5 April 1926 |
| Birth Place: | Geidučiai, Klaipėda County, Lithuania |
| Death Place: | Telšiai, Telšiai County, Lithuania |
| Previous Post: | Titular Bishop of Sullectum (1982–1989) |
| Buried: | Telšiai Cathedral |
| Nationality: | Lithuanian |
Antanas Vaičius (5 April 1926 – 25 November 2008) was a Lithuanian Roman Catholic prelate, who served as an Apostolic Administrator (1982–1989) and Diocesan Bishop (1989–2001) of the Roman Catholic Diocese of Telšiai.
Born in Geidučiai, present day Skuodas District Municipality, in a farmers family with four sisters and one brother, Antanas Vaičius during 1934–1943 studied in Šačiai, Mosėdis and Skuodas schools and joined to the Telšiai Bishop Vincentas Borisevičius Priest Seminary, where studied until 1946, when this seminary was closed by Soviets. From 1946 to 1951 he studied in the Kaunas Priest Seminary.[1] During his studies, he was ordained to the priesthood for the Diocese of Telšiai by bishop Kazimieras Paltarokas on 24 September 1950.
Father Vaičius worked as an assistant priest, and after – as a parish priest in a various parishes of the Diocese of Telšiai: Plungė, Žygaičiai, Klaipėda, Salantai, Lauko Soda, Akmenė, Viekšniai and Telšiai. On 3 October 1975 he was elected as a Vicar Capitluar for the vacant Diocese of Telšiai and in 1982 – for the Roman Catholic Territorial Prelature of Klaipėda.[1]
On 5 July 1982, Pope John Paul II appointed him Titular Bishop of Sullectum and Apostolic Administrator of the Roman Catholic Diocese of Telšiai. Bishop Vaičius received his episcopal consecration on 25 July 1982 in the Cathedral Basilica of apostles St. Peter and St. Paul of Kaunas from Bishop Liudas Povilonis, with Bishops Romualdas Krikšciunas and Vincentas Sladkevičius as co-consecrators. During 1988–1993 he served as the vice-president of the Lithuanian Bishops' Conference.
Bishop Vaičius retired on 26 May 2001, after reaching the age limit of 75 years old[1] and lived in Telšiai.